-69.88% is the change from 166 to 50
Calculation steps:
[( 50 - 166 ) ÷ 166] x 100 = -69.88%
Formula
Percentage change = [(50 - 166) / 166] x 100
Subtract the new number by the original number
50 - 166 = -116
-116 ÷ 166 = -0.6987951807228916
-0.6987951807228916 x 100 = -69.88%