-91.92% is the change from 631 to 51
Calculation steps:
[( 51 - 631 ) ÷ 631] x 100 = -91.92%
Formula
Percentage change = [(51 - 631) / 631] x 100
Subtract the new number by the original number
51 - 631 = -580
-580 ÷ 631 = -0.919175911251981
-0.919175911251981 x 100 = -91.92%