-91.01% is the change from 345 to 31
Calculation steps:
[( 31 - 345 ) ÷ 345] x 100 = -91.01%
Formula
Percentage change = [(31 - 345) / 345] x 100
Subtract the new number by the original number
31 - 345 = -314
-314 ÷ 345 = -0.9101449275362319
-0.9101449275362319 x 100 = -91.01%