-45.45% is the change from 121 to 66
Calculation steps:
[( 66 - 121 ) ÷ 121] x 100 = -45.45%
Formula
Percentage change = [(66 - 121) / 121] x 100
Subtract the new number by the original number
66 - 121 = -55
-55 ÷ 121 = -0.45454545454545453
-0.45454545454545453 x 100 = -45.45%