What is FCF 3y?


Hi. I have a question.
1.What is the exact meaning of FCF 3Y? Is the average growth rate for FCF 3 years? Or is it total?
2.What's the formula? For example, in the case of ticker name 'CZR', in cashflow, fcf/share for the last three years is 2019 ($1.82), 2020 (-$6.01), and 2021 ($1.61); fcf 3y is 205.90%. How does this come to be?