6.6% is the change from 606 to 646
Calculation steps:
[( 646 - 606 ) ÷ 606] x 100 = 6.6%
Formula
Percentage change = [(646 - 606) / 606] x 100
Subtract the new number by the original number
646 - 606 = 40
40 ÷ 606 = 0.066006600660066
0.066006600660066 x 100 = 6.6%