2.24% is the change from 670 to 685
Calculation steps:
[( 685 - 670 ) ÷ 670] x 100 = 2.24%
Formula
Percentage change = [(685 - 670) / 670] x 100
Subtract the new number by the original number
685 - 670 = 15
15 ÷ 670 = 0.022388059701492536
0.022388059701492536 x 100 = 2.24%