-66.62% is the change from 770 to 257
Calculation steps:
[( 257 - 770 ) ÷ 770] x 100 = -66.62%
Formula
Percentage change = [(257 - 770) / 770] x 100
Subtract the new number by the original number
257 - 770 = -513
-513 ÷ 770 = -0.6662337662337663
-0.6662337662337663 x 100 = -66.62%