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Changes in our Level 3 defined benefit plan assets during 2020 and 2019 were as follows: 

<img src='content_image/1059500.jpg'>

## S. SEGMENT INFORMATION 

We have four operating segments: Aerospace, Marine Systems, Combat Systems and Technologies. We organize our segments in accordance with the nature of products and services offered. We measure each segment’s profitability based on operating earnings. As a result, we do not allocate net interest, other income and expense items, and income taxes to our segments. 

Summary financial information for each of our segments follows: 

<img src='content_image/1059508.jpg'>

* See Note B for additional revenue information by segment. 

Corporate operating results consist primarily of equity-based compensation expense. Corporate operating results in 2018 also included one-time charges of approximately $45 associated with the costs to complete the CSRA acquisition. 

