-67.65% is the change from 646 to 209
Calculation steps:
[( 209 - 646 ) ÷ 646] x 100 = -67.65%
Formula
Percentage change = [(209 - 646) / 646] x 100
Subtract the new number by the original number
209 - 646 = -437
-437 ÷ 646 = -0.6764705882352942
-0.6764705882352942 x 100 = -67.65%