-9.71% is the change from 340 to 307
Calculation steps:
[( 307 - 340 ) ÷ 340] x 100 = -9.71%
Formula
Percentage change = [(307 - 340) / 340] x 100
Subtract the new number by the original number
307 - 340 = -33
-33 ÷ 340 = -0.09705882352941177
-0.09705882352941177 x 100 = -9.71%