-67.5% is the change from 643 to 209
Calculation steps:
[( 209 - 643 ) ÷ 643] x 100 = -67.5%
Formula
Percentage change = [(209 - 643) / 643] x 100
Subtract the new number by the original number
209 - 643 = -434
-434 ÷ 643 = -0.6749611197511665
-0.6749611197511665 x 100 = -67.5%