-66.36% is the change from 645 to 217
Calculation steps:
[( 217 - 645 ) ÷ 645] x 100 = -66.36%
Formula
Percentage change = [(217 - 645) / 645] x 100
Subtract the new number by the original number
217 - 645 = -428
-428 ÷ 645 = -0.6635658914728683
-0.6635658914728683 x 100 = -66.36%