-93.21% is the change from 221 to 15
Calculation steps:
[( 15 - 221 ) ÷ 221] x 100 = -93.21%
Formula
Percentage change = [(15 - 221) / 221] x 100
Subtract the new number by the original number
15 - 221 = -206
-206 ÷ 221 = -0.9321266968325792
-0.9321266968325792 x 100 = -93.21%