-16.5% is the change from 600 to 501
Calculation steps:
[( 501 - 600 ) ÷ 600] x 100 = -16.5%
Formula
Percentage change = [(501 - 600) / 600] x 100
Subtract the new number by the original number
501 - 600 = -99
-99 ÷ 600 = -0.165
-0.165 x 100 = -16.5%