-76.32% is the change from 342 to 81
Calculation steps:
[( 81 - 342 ) ÷ 342] x 100 = -76.32%
Formula
Percentage change = [(81 - 342) / 342] x 100
Subtract the new number by the original number
81 - 342 = -261
-261 ÷ 342 = -0.7631578947368421
-0.7631578947368421 x 100 = -76.32%