-73.7% is the change from 521 to 137
Calculation steps:
[( 137 - 521 ) ÷ 521] x 100 = -73.7%
Formula
Percentage change = [(137 - 521) / 521] x 100
Subtract the new number by the original number
137 - 521 = -384
-384 ÷ 521 = -0.7370441458733206
-0.7370441458733206 x 100 = -73.7%