78.61% is the change from 173 to 309
Calculation steps:
[( 309 - 173 ) ÷ 173] x 100 = 78.61%
Formula
Percentage change = [(309 - 173) / 173] x 100
Subtract the new number by the original number
309 - 173 = 136
136 ÷ 173 = 0.7861271676300579
0.7861271676300579 x 100 = 78.61%