419.7% is the change from 66 to 343
Calculation steps:
[( 343 - 66 ) ÷ 66] x 100 = 419.7%
Formula
Percentage change = [(343 - 66) / 66] x 100
Subtract the new number by the original number
343 - 66 = 277
277 ÷ 66 = 4.196969696969697
4.196969696969697 x 100 = 419.7%