-7.14% is the change from 42 to 39
Calculation steps:
[( 39 - 42 ) ÷ 42] x 100 = -7.14%
Formula
Percentage change = [(39 - 42) / 42] x 100
Subtract the new number by the original number
39 - 42 = -3
-3 ÷ 42 = -0.07142857142857142
-0.07142857142857142 x 100 = -7.14%