3.73% is the change from 509 to 528
Calculation steps:
[( 528 - 509 ) ÷ 509] x 100 = 3.73%
Formula
Percentage change = [(528 - 509) / 509] x 100
Subtract the new number by the original number
528 - 509 = 19
19 ÷ 509 = 0.03732809430255403
0.03732809430255403 x 100 = 3.73%