-33.6% is the change from 634 to 421
Calculation steps:
[( 421 - 634 ) ÷ 634] x 100 = -33.6%
Formula
Percentage change = [(421 - 634) / 634] x 100
Subtract the new number by the original number
421 - 634 = -213
-213 ÷ 634 = -0.3359621451104101
-0.3359621451104101 x 100 = -33.6%