-20.28% is the change from 641 to 511
Calculation steps:
[( 511 - 641 ) ÷ 641] x 100 = -20.28%
Formula
Percentage change = [(511 - 641) / 641] x 100
Subtract the new number by the original number
511 - 641 = -130
-130 ÷ 641 = -0.20280811232449297
-0.20280811232449297 x 100 = -20.28%