-92.04% is the change from 641 to 51
Calculation steps:
[( 51 - 641 ) ÷ 641] x 100 = -92.04%
Formula
Percentage change = [(51 - 641) / 641] x 100
Subtract the new number by the original number
51 - 641 = -590
-590 ÷ 641 = -0.9204368174726989
-0.9204368174726989 x 100 = -92.04%