-32.5% is the change from 643 to 434
Calculation steps:
[( 434 - 643 ) ÷ 643] x 100 = -32.5%
Formula
Percentage change = [(434 - 643) / 643] x 100
Subtract the new number by the original number
434 - 643 = -209
-209 ÷ 643 = -0.3250388802488336
-0.3250388802488336 x 100 = -32.5%