-80.77% is the change from 78 to 15
Calculation steps:
[( 15 - 78 ) ÷ 78] x 100 = -80.77%
Formula
Percentage change = [(15 - 78) / 78] x 100
Subtract the new number by the original number
15 - 78 = -63
-63 ÷ 78 = -0.8076923076923077
-0.8076923076923077 x 100 = -80.77%