10. Segment reporting The Companys reportable segments were determined on the same basis as how management evaluates performance internally by the Chief Operating Decision Maker (CODM). The Company has determined that the Chief Executive Officer is the CODM and the Companys two reportable segments consist of TCS and Elfa. The TCS segment includes the Companys retail stores, website and call center, as well as the installation and organization services business. The Elfa segment includes the manufacturing business that produces the elfa  brand products that are sold domestically exclusively through the TCS segment, as well as on a wholesale basis in approximately 30 countries around the world with a concentration in the Nordic region of Europe. The intersegment sales in the Elfa column represent elfa  product sales to the TCS segment. These sales and the related gross margin on merchandise recorded in TCS inventory balances at the end of the period are eliminated for consolidation purposes in the Eliminations column. The net sales to third parties in the Elfa column represent sales to customers outside of the United States. The Company has determined that adjusted earnings before interest, tax, depreciation, and amortization (Adjusted EBITDA) is the profit or loss measure that the CODM uses to make resource allocation decisions and evaluate segment performance. Adjusted EBITDA assists management in comparing our performance on a consistent basis for purposes of business decision-making by removing the impact of certain items that management believes do not directly reflect our core operations and, therefore, are not included in measuring segment performance. Adjusted EBITDA is calculated in accordance with the Senior Secured Term Loan Facility and the Revolving Credit Facility and we define Adjusted EBITDA as net income before interest, taxes, depreciation and amortization, certain non-cash items, and other adjustments that we do not consider in our evaluation of ongoing operating performance from period to period. Thirteen Weeks Ended December 28, 2019 TCS Elfa Eliminations Total Net sales to third parties $ 211,971 $ 16,686 $  $ 228,657 Intersegment sales  21,385 (21,385)  Adjusted EBITDA 17,924 6,118 (2,035) 22,007 Interest expense, net 5,056 78  5,134 Assets (1) 1,049,889 119,321 (26,928) 1,142,282 Thirteen Weeks Ended December 29, 2018 TCS Elfa Eliminations Total Net sales to third parties $ 204,899 $ 16,738 $  $ 221,637 Intersegment sales  22,369 (22,369)  Adjusted EBITDA 19,014 4,994 (2,192) 21,816 Interest expense, net 5,957 51  6,008 Assets (1) 671,865 105,491 (5,334) 772,022 Thirty-Nine Weeks Ended December 28, 2019 TCS Elfa Eliminations Total Net sales to third parties $ 628,282 $ 46,327 $  $ 674,609 Intersegment sales  53,800 (53,800)  Adjusted EBITDA 46,820 14,155 (5,899) 55,076 Interest expense, net 15,960 285  16,245 Assets (1) 1,049,889 119,321 (26,928) 1,142,282 Thirty-Nine Weeks Ended December 29, 2018 TCS Elfa Eliminations Total Net sales to third parties $ 593,896 $ 48,017 $  $ 641,913 Intersegment sales  47,414 (47,414)  Adjusted EBITDA 50,345 10,432 (2,223) 58,554 Interest expense, net 21,097 196  21,293 Assets (1) 671,865 105,491 (5,334) 772,022 (1) Tangible assets in the Elfa column are located outside of the United States. A reconciliation of income (loss) before taxes to Adjusted EBITDA is set forth below: Thirteen Weeks Ended Thirty-Nine Weeks Ended December 28, December 29, December 28, December 29, 2019 2018 2019 2018 Income (loss) before taxes $ 4,298 $ 5,395 $ 3,387 $ (191) Add: Depreciation and amortization 9,689 8,887 28,137 27,352 Interest expense, net 5,134 6,008 16,245 21,293 Pre-opening costs (a) 2,482 691 5,988 1,918 Non-cash lease expense (b) (355) 101 (1,532) (1,117) Stock-based compensation (c) 799 632 2,575 1,987 Loss on extinguishment of debt (d)    2,082 Foreign exchange (gains) losses (e) (37) 22 (98) 69 Optimization Plan implementation charges (f)    4,864 Elfa France closure (g) (1)  402  Other adjustments (h) (2) 80 (28) 297 Adjusted EBITDA $ 22,007 $ 21,816 $ 55,076 $ 58,554 (a) Non-capital expenditures associated with opening new stores, relocating stores, and net costs associated with opening the second distribution center, including marketing expenses, travel and relocation costs, and training costs. We adjust for these costs to facilitate comparisons of our performance from period to period. (b) Reflects the extent to which our annual GAAP operating lease expense has been above or below our cash operating lease payments. The amount varies depending on the average age of our lease portfolio (weighted for size), as our GAAP operating lease expense on younger leases typically exceeds our cash operating lease payments, while our GAAP operating lease expense on older leases is typically less than our cash operating lease payments. In the thirteen and thirty-nine weeks ended December 28, 2019, lease expenses associated with the opening of the second distribution center were excluded from Non-cash lease expense and included in Pre-opening costs. (c) Non-cash charges related to stock-based compensation programs, which vary from period to period depending on volume and vesting timing of awards. We adjust for these charges to facilitate comparisons from period to period. (d) Loss recorded as a result of the amendments made to the Senior Secured Term Loan Facility in September 2018, which we do not consider in our evaluation of our ongoing operations. (e) Realized foreign exchange transactional gains/losses our management does not consider in our evaluation of our ongoing operations. (f) Charges incurred to implement our four-part optimization plan to drive improved sales and profitability, launched during fiscal 2017 (the Optimization Plan), which include certain consulting costs recorded in SG&amp;A in the first quarter of fiscal 2018, which we do not consider in our evaluation of ongoing performance. (g) Charges related to the closure of Elfa France operations in the second quarter of fiscal 2019, which we do not consider in our evaluation of ongoing performance . (h) Other adjustments include amounts our management does not consider in our evaluation of our ongoing operations, including certain severance and other charges.