-30% is the change from 620 to 434
Calculation steps:
[( 434 - 620 ) ÷ 620] x 100 = -30%
Formula
Percentage change = [(434 - 620) / 620] x 100
Subtract the new number by the original number
434 - 620 = -186
-186 ÷ 620 = -0.3
-0.3 x 100 = -30%
Example