-99.61% is the change from 509 to 2
Calculation steps:
[( 2 - 509 ) ÷ 509] x 100 = -99.61%
Formula
Percentage change = [(2 - 509) / 509] x 100
Subtract the new number by the original number
2 - 509 = -507
-507 ÷ 509 = -0.9960707269155207
-0.9960707269155207 x 100 = -99.61%