-17.67% is the change from 645 to 531
Calculation steps:
[( 531 - 645 ) ÷ 645] x 100 = -17.67%
Formula
Percentage change = [(531 - 645) / 645] x 100
Subtract the new number by the original number
531 - 645 = -114
-114 ÷ 645 = -0.17674418604651163
-0.17674418604651163 x 100 = -17.67%