-50.96% is the change from 991 to 486
Calculation steps:
[( 486 - 991 ) ÷ 991] x 100 = -50.96%
Formula
Percentage change = [(486 - 991) / 991] x 100
Subtract the new number by the original number
486 - 991 = -505
-505 ÷ 991 = -0.5095862764883956
-0.5095862764883956 x 100 = -50.96%