-19.6% is the change from 648 to 521
Calculation steps:
[( 521 - 648 ) ÷ 648] x 100 = -19.6%
Formula
Percentage change = [(521 - 648) / 648] x 100
Subtract the new number by the original number
521 - 648 = -127
-127 ÷ 648 = -0.19598765432098766
-0.19598765432098766 x 100 = -19.6%