-6.41% is the change from 343 to 321
Calculation steps:
[( 321 - 343 ) ÷ 343] x 100 = -6.41%
Formula
Percentage change = [(321 - 343) / 343] x 100
Subtract the new number by the original number
321 - 343 = -22
-22 ÷ 343 = -0.0641399416909621
-0.0641399416909621 x 100 = -6.41%