-80.16% is the change from 509 to 101
Calculation steps:
[( 101 - 509 ) ÷ 509] x 100 = -80.16%
Formula
Percentage change = [(101 - 509) / 509] x 100
Subtract the new number by the original number
101 - 509 = -408
-408 ÷ 509 = -0.8015717092337917
-0.8015717092337917 x 100 = -80.16%