-87.9% is the change from 347 to 42
Calculation steps:
[( 42 - 347 ) ÷ 347] x 100 = -87.9%
Formula
Percentage change = [(42 - 347) / 347] x 100
Subtract the new number by the original number
42 - 347 = -305
-305 ÷ 347 = -0.8789625360230547
-0.8789625360230547 x 100 = -87.9%