77.55% is the change from 343 to 609
Calculation steps:
[( 609 - 343 ) ÷ 343] x 100 = 77.55%
Formula
Percentage change = [(609 - 343) / 343] x 100
Subtract the new number by the original number
609 - 343 = 266
266 ÷ 343 = 0.7755102040816326
0.7755102040816326 x 100 = 77.55%