-73.3% is the change from 191 to 51
Calculation steps:
[( 51 - 191 ) ÷ 191] x 100 = -73.3%
Formula
Percentage change = [(51 - 191) / 191] x 100
Subtract the new number by the original number
51 - 191 = -140
-140 ÷ 191 = -0.7329842931937173
-0.7329842931937173 x 100 = -73.3%