970% is the change from 30 to 321
Calculation steps:
[( 321 - 30 ) ÷ 30] x 100 = 970%
Formula
Percentage change = [(321 - 30) / 30] x 100
Subtract the new number by the original number
321 - 30 = 291
291 ÷ 30 = 9.7
9.7 x 100 = 970%
Example