-51.66% is the change from 511 to 247
Calculation steps:
[( 247 - 511 ) ÷ 511] x 100 = -51.66%
Formula
Percentage change = [(247 - 511) / 511] x 100
Subtract the new number by the original number
247 - 511 = -264
-264 ÷ 511 = -0.5166340508806262
-0.5166340508806262 x 100 = -51.66%