-36.76% is the change from 340 to 215
Calculation steps:
[( 215 - 340 ) ÷ 340] x 100 = -36.76%
Formula
Percentage change = [(215 - 340) / 340] x 100
Subtract the new number by the original number
215 - 340 = -125
-125 ÷ 340 = -0.36764705882352944
-0.36764705882352944 x 100 = -36.76%