-19.76% is the change from 501 to 402
Calculation steps:
[( 402 - 501 ) ÷ 501] x 100 = -19.76%
Formula
Percentage change = [(402 - 501) / 501] x 100
Subtract the new number by the original number
402 - 501 = -99
-99 ÷ 501 = -0.19760479041916168
-0.19760479041916168 x 100 = -19.76%