-36.06% is the change from 502 to 321
Calculation steps:
[( 321 - 502 ) ÷ 502] x 100 = -36.06%
Formula
Percentage change = [(321 - 502) / 502] x 100
Subtract the new number by the original number
321 - 502 = -181
-181 ÷ 502 = -0.3605577689243028
-0.3605577689243028 x 100 = -36.06%