-39.24% is the change from 502 to 305
Calculation steps:
[( 305 - 502 ) ÷ 502] x 100 = -39.24%
Formula
Percentage change = [(305 - 502) / 502] x 100
Subtract the new number by the original number
305 - 502 = -197
-197 ÷ 502 = -0.39243027888446214
-0.39243027888446214 x 100 = -39.24%