Good question...it's derived from the (hidden) 383(294+89) then compounded into %'s] then decimaled minus to 53.2] the read then becomes substantial...
divide ^3^ into +883=294.1 ] into -250=89.1 ] 205 thus, becomes the difference. this is basic, depending on your comprehension level of math, and sheparding technique of applied formula's, you may continue for a more in-depth read, or accept the 'basic'..to continue:
+883 becomes 8.83
-250 becomes 2.50
+533 stays 533 exclude +
294 becomes 29.4
89 becomes 8.9
205 stays the same
+76.7% becomes 7.6
-23.2% becomes 2.3
53.2 becomes 53.2%