-48.44% is the change from 991 to 511
Calculation steps:
[( 511 - 991 ) ÷ 991] x 100 = -48.44%
Formula
Percentage change = [(511 - 991) / 991] x 100
Subtract the new number by the original number
511 - 991 = -480
-480 ÷ 991 = -0.4843592330978809
-0.4843592330978809 x 100 = -48.44%