-73.08% is the change from 509 to 137
Calculation steps:
[( 137 - 509 ) ÷ 509] x 100 = -73.08%
Formula
Percentage change = [(137 - 509) / 509] x 100
Subtract the new number by the original number
137 - 509 = -372
-372 ÷ 509 = -0.730844793713163
-0.730844793713163 x 100 = -73.08%