-20.03% is the change from 644 to 515
Calculation steps:
[( 515 - 644 ) ÷ 644] x 100 = -20.03%
Formula
Percentage change = [(515 - 644) / 644] x 100
Subtract the new number by the original number
515 - 644 = -129
-129 ÷ 644 = -0.20031055900621117
-0.20031055900621117 x 100 = -20.03%