-49.4% is the change from 83 to 42
Calculation steps:
[( 42 - 83 ) ÷ 83] x 100 = -49.4%
Formula
Percentage change = [(42 - 83) / 83] x 100
Subtract the new number by the original number
42 - 83 = -41
-41 ÷ 83 = -0.4939759036144578
-0.4939759036144578 x 100 = -49.4%