30.98% is the change from 397 to 520
Calculation steps:
[( 520 - 397 ) ÷ 397] x 100 = 30.98%
Formula
Percentage change = [(520 - 397) / 397] x 100
Subtract the new number by the original number
520 - 397 = 123
123 ÷ 397 = 0.30982367758186397
0.30982367758186397 x 100 = 30.98%