assets, including $3.6 billion for the Permian and $1.6 billion for other shale and tight rock investments. Approximately $5.1 billion of the upstream program is planned for major capital projects underway, including $4.3 billion associated with the Future Growth and Wellhead Pressure Management Project at the Tengiz field in Kazakhstan. Global exploration funding is expected to be about $1.3 billion. Remaining upstream spend is budgeted for early stage projects supporting potential future developments. The company will continue to monitor crude oil market conditions and expects to further restrict capital outlays should oil price conditions deteriorate.

Worldwide downstream spending in 2019 is estimated to be $2.5 billion, with $1.5 billion estimated for projects in the United States.

Investments in technology businesses and other corporate operations in 2019 are budgeted at $0.2 billion.

Noncontrolling Interests The company had noncontrolling interests of $1.1 billion at December 31, 2018 and $1.2 billion at December 31, 2017. Distributions to noncontrolling interests totaled $91 million and $78 million in 2018 and 2017, respectively.

Pension Obligations Information related to pension plan contributions is included beginning on page 81 in Note 22, Employee Benefit Plans, under the heading “Cash Contributions and Benefit Payments.”

Financial Ratios

Current Ratio Current assets divided by current liabilities, which indicates the company’s ability to repay its short-term liabilities with short-term assets. The current ratio in all periods was adversely affected by the fact that Chevron’s inventories are valued on a last-in, first-out basis. At year-end 2018, the book value of inventory was lower than replacement costs, based on average acquisition costs during the year, by approximately $5.1 billion.

Interest Coverage Ratio Income before income tax expense, plus interest and debt expense and amortization of capitalized interest, less net income attributable to noncontrolling interests, divided by before-tax interest costs. This ratio indicates the company’s ability to pay interest on outstanding debt. The company’s interest coverage ratio in 2018 was higher than 2017 and 2016 due to higher income.

Debt Ratio Total debt as a percentage of total debt plus Chevron Corporation Stockholders' Equity, which indicates the company’s leverage. The company's debt ratio was 18.2 percent at year-end 2018, compared with 20.7 percent and 24.1 percent at year-end 2017 and 2016, respectively.

Off-Balance-Sheet Arrangements, Contractual Obligations, Guarantees and Other Contingencies

Long-Term Unconditional Purchase Obligations and Commitments, Including Throughput and Take-or-Pay Agreements Information related to these matters is included on page 86 in Note 23, Other Contingencies and Commitments.

Direct Guarantees

Additional information related to guarantees is included on page 86 in Note 23, Other Contingencies and Commitments.

Indemnifications Information related to indemnifications is included on page 86 in Note 23, Other Contingencies and Commitments.

Financial and Derivative Instrument Market Risk

The market risk associated with the