-39.51% is the change from 81 to 49
Calculation steps:
[( 49 - 81 ) ÷ 81] x 100 = -39.51%
Formula
Percentage change = [(49 - 81) / 81] x 100
Subtract the new number by the original number
49 - 81 = -32
-32 ÷ 81 = -0.3950617283950617
-0.3950617283950617 x 100 = -39.51%