-50.88% is the change from 511 to 251
Calculation steps:
[( 251 - 511 ) ÷ 511] x 100 = -50.88%
Formula
Percentage change = [(251 - 511) / 511] x 100
Subtract the new number by the original number
251 - 511 = -260
-260 ÷ 511 = -0.5088062622309197
-0.5088062622309197 x 100 = -50.88%