-92.42% is the change from 660 to 50
Calculation steps:
[( 50 - 660 ) ÷ 660] x 100 = -92.42%
Formula
Percentage change = [(50 - 660) / 660] x 100
Subtract the new number by the original number
50 - 660 = -610
-610 ÷ 660 = -0.9242424242424242
-0.9242424242424242 x 100 = -92.42%