-50% is the change from 434 to 217
Calculation steps:
[( 217 - 434 ) ÷ 434] x 100 = -50%
Formula
Percentage change = [(217 - 434) / 434] x 100
Subtract the new number by the original number
217 - 434 = -217
-217 ÷ 434 = -0.5
-0.5 x 100 = -50%
Example