-34.62% is the change from 491 to 321
Calculation steps:
[( 321 - 491 ) ÷ 491] x 100 = -34.62%
Formula
Percentage change = [(321 - 491) / 491] x 100
Subtract the new number by the original number
321 - 491 = -170
-170 ÷ 491 = -0.34623217922606925
-0.34623217922606925 x 100 = -34.62%