-99.71% is the change from 340 to 1
Calculation steps:
[( 1 - 340 ) ÷ 340] x 100 = -99.71%
Formula
Percentage change = [(1 - 340) / 340] x 100
Subtract the new number by the original number
1 - 340 = -339
-339 ÷ 340 = -0.9970588235294118
-0.9970588235294118 x 100 = -99.71%