341.43% is the change from 70 to 309
Calculation steps:
[( 309 - 70 ) ÷ 70] x 100 = 341.43%
Formula
Percentage change = [(309 - 70) / 70] x 100
Subtract the new number by the original number
309 - 70 = 239
239 ÷ 70 = 3.414285714285714
3.414285714285714 x 100 = 341.43%