-47.06% is the change from 340 to 180
Calculation steps:
[( 180 - 340 ) ÷ 340] x 100 = -47.06%
Formula
Percentage change = [(180 - 340) / 340] x 100
Subtract the new number by the original number
180 - 340 = -160
-160 ÷ 340 = -0.47058823529411764
-0.47058823529411764 x 100 = -47.06%