-34.83% is the change from 646 to 421
Calculation steps:
[( 421 - 646 ) ÷ 646] x 100 = -34.83%
Formula
Percentage change = [(421 - 646) / 646] x 100
Subtract the new number by the original number
421 - 646 = -225
-225 ÷ 646 = -0.34829721362229105
-0.34829721362229105 x 100 = -34.83%