-70.59% is the change from 340 to 100
Calculation steps:
[( 100 - 340 ) ÷ 340] x 100 = -70.59%
Formula
Percentage change = [(100 - 340) / 340] x 100
Subtract the new number by the original number
100 - 340 = -240
-240 ÷ 340 = -0.7058823529411765
-0.7058823529411765 x 100 = -70.59%