The graph below shows the approximate average annual ocean heat content from 1993 to 2020. It was created using data from NOAA. Line 1 represents ocean levels from the surface to 2,300 feet below ocean surface. Line 2 represents ocean levels from 2,300 feet to 6,560 feet below ocean surface.

Which statement describes the approximate average trend of ocean heat content between 2,300 and 6,560 feet under the ocean during this time period?

- An increase of about 130 x 1021 joules
- An increase of about 80 x 1021 joules
- A decrease of about 20 x 1021 joules
- A decrease of about 80 x 1021 joules