-1.96% is the change from 51 to 50
Calculation steps:
[( 50 - 51 ) ÷ 51] x 100 = -1.96%
Formula
Percentage change = [(50 - 51) / 51] x 100
Subtract the new number by the original number
50 - 51 = -1
-1 ÷ 51 = -0.0196078431372549
-0.0196078431372549 x 100 = -1.96%