-69.28% is the change from 166 to 51
Calculation steps:
[( 51 - 166 ) ÷ 166] x 100 = -69.28%
Formula
Percentage change = [(51 - 166) / 166] x 100
Subtract the new number by the original number
51 - 166 = -115
-115 ÷ 166 = -0.6927710843373494
-0.6927710843373494 x 100 = -69.28%