-74.04% is the change from 990 to 257
Calculation steps:
[( 257 - 990 ) ÷ 990] x 100 = -74.04%
Formula
Percentage change = [(257 - 990) / 990] x 100
Subtract the new number by the original number
257 - 990 = -733
-733 ÷ 990 = -0.7404040404040404
-0.7404040404040404 x 100 = -74.04%