-66.98% is the change from 639 to 211
Calculation steps:
[( 211 - 639 ) ÷ 639] x 100 = -66.98%
Formula
Percentage change = [(211 - 639) / 639] x 100
Subtract the new number by the original number
211 - 639 = -428
-428 ÷ 639 = -0.6697965571205008
-0.6697965571205008 x 100 = -66.98%