-68.08% is the change from 520 to 166
Calculation steps:
[( 166 - 520 ) ÷ 520] x 100 = -68.08%
Formula
Percentage change = [(166 - 520) / 520] x 100
Subtract the new number by the original number
166 - 520 = -354
-354 ÷ 520 = -0.6807692307692308
-0.6807692307692308 x 100 = -68.08%