-17.07% is the change from 621 to 515
Calculation steps:
[( 515 - 621 ) ÷ 621] x 100 = -17.07%
Formula
Percentage change = [(515 - 621) / 621] x 100
Subtract the new number by the original number
515 - 621 = -106
-106 ÷ 621 = -0.1706924315619968
-0.1706924315619968 x 100 = -17.07%