-94.85% is the change from 991 to 51
Calculation steps:
[( 51 - 991 ) ÷ 991] x 100 = -94.85%
Formula
Percentage change = [(51 - 991) / 991] x 100
Subtract the new number by the original number
51 - 991 = -940
-940 ÷ 991 = -0.9485368314833501
-0.9485368314833501 x 100 = -94.85%