-17.58% is the change from 620 to 511
Calculation steps:
[( 511 - 620 ) ÷ 620] x 100 = -17.58%
Formula
Percentage change = [(511 - 620) / 620] x 100
Subtract the new number by the original number
511 - 620 = -109
-109 ÷ 620 = -0.17580645161290323
-0.17580645161290323 x 100 = -17.58%