-97.82% is the change from 688 to 15
Calculation steps:
[( 15 - 688 ) ÷ 688] x 100 = -97.82%
Formula
Percentage change = [(15 - 688) / 688] x 100
Subtract the new number by the original number
15 - 688 = -673
-673 ÷ 688 = -0.9781976744186046
-0.9781976744186046 x 100 = -97.82%