-23.4% is the change from 641 to 491
Calculation steps:
[( 491 - 641 ) ÷ 641] x 100 = -23.4%
Formula
Percentage change = [(491 - 641) / 641] x 100
Subtract the new number by the original number
491 - 641 = -150
-150 ÷ 641 = -0.23400936037441497
-0.23400936037441497 x 100 = -23.4%