-83.86% is the change from 409 to 66
Calculation steps:
[( 66 - 409 ) ÷ 409] x 100 = -83.86%
Formula
Percentage change = [(66 - 409) / 409] x 100
Subtract the new number by the original number
66 - 409 = -343
-343 ÷ 409 = -0.8386308068459658
-0.8386308068459658 x 100 = -83.86%