-81.29% is the change from 342 to 64
Calculation steps:
[( 64 - 342 ) ÷ 342] x 100 = -81.29%
Formula
Percentage change = [(64 - 342) / 342] x 100
Subtract the new number by the original number
64 - 342 = -278
-278 ÷ 342 = -0.8128654970760234
-0.8128654970760234 x 100 = -81.29%