-51.18% is the change from 340 to 166
Calculation steps:
[( 166 - 340 ) ÷ 340] x 100 = -51.18%
Formula
Percentage change = [(166 - 340) / 340] x 100
Subtract the new number by the original number
166 - 340 = -174
-174 ÷ 340 = -0.5117647058823529
-0.5117647058823529 x 100 = -51.18%