-37.67% is the change from 515 to 321
Calculation steps:
[( 321 - 515 ) ÷ 515] x 100 = -37.67%
Formula
Percentage change = [(321 - 515) / 515] x 100
Subtract the new number by the original number
321 - 515 = -194
-194 ÷ 515 = -0.3766990291262136
-0.3766990291262136 x 100 = -37.67%