-17.74% is the change from 620 to 510
Calculation steps:
[( 510 - 620 ) ÷ 620] x 100 = -17.74%
Formula
Percentage change = [(510 - 620) / 620] x 100
Subtract the new number by the original number
510 - 620 = -110
-110 ÷ 620 = -0.1774193548387097
-0.1774193548387097 x 100 = -17.74%