-49.39% is the change from 990 to 501
Calculation steps:
[( 501 - 990 ) ÷ 990] x 100 = -49.39%
Formula
Percentage change = [(501 - 990) / 990] x 100
Subtract the new number by the original number
501 - 990 = -489
-489 ÷ 990 = -0.49393939393939396
-0.49393939393939396 x 100 = -49.39%