what does this graph of free cash flow tell about the company?

2017 2020 TTM operating cash flow less capital expense free cash flow 2016 -2,957,000,000 -3991000000.00 -4,929,000,000 -2994000000.00 2018 2019 3,894,000,000 5,930,000,000 -2584000000.00 -1970000000.00 1310000000.00 3960000000.00 6,226,000,000 -1387000000.00 4,696,000,000 -1283000000.00 3413000000.00 6948000000.00 -7923000000.00 4839000000.00 less capital expense is calculated by the sum of the capital expenses reported and purchase property plant etc. capital expense reported -3,804,000,000 purchase property, plant et - 187,000,000 -2,807,000,000 -187,000,000 -2,538,000,000 - 46,000,000 -1,961,000,000 -9,000,000 -1,252,000,000 -135,000,000 -1,146,000,000 -137000000 free cash flow 6000000000 4000000000 2000000000 -2000000000 -4000000000 -6000000000 -8000000000 -10000000000 2016 2017 2018 2019 2020 TTM -operating cash flow less capital expense -3991000000.0-299 4000000.0-2584000000.0-1970000000.0-1387000000.0 1283000000.0 free cash flow -694 8000000.0-792 3000000.0131000000 0.008960000000.00483 900000 0.008413000000.00 operating cash flow less capital expense free cash flow