-60.78% is the change from 51 to 20
Calculation steps:
[( 20 - 51 ) ÷ 51] x 100 = -60.78%
Formula
Percentage change = [(20 - 51) / 51] x 100
Subtract the new number by the original number
20 - 51 = -31
-31 ÷ 51 = -0.6078431372549019
-0.6078431372549019 x 100 = -60.78%