-97.01% is the change from 502 to 15
Calculation steps:
[( 15 - 502 ) ÷ 502] x 100 = -97.01%
Formula
Percentage change = [(15 - 502) / 502] x 100
Subtract the new number by the original number
15 - 502 = -487
-487 ÷ 502 = -0.9701195219123506
-0.9701195219123506 x 100 = -97.01%