-49.71% is the change from 340 to 171
Calculation steps:
[( 171 - 340 ) ÷ 340] x 100 = -49.71%
Formula
Percentage change = [(171 - 340) / 340] x 100
Subtract the new number by the original number
171 - 340 = -169
-169 ÷ 340 = -0.4970588235294118
-0.4970588235294118 x 100 = -49.71%