=SUMPRODUCT((MONTH($A$2:$A$36)<=6)*(MONTH($A$2:$A$36)>=4)*$B$2:$B$36)
=CHOOSE(MATCH(Sheet1!$G$2,Sheet1!$I$2:$I$18,0),1,2,3,4,5,6,7,8,9,10,11,12,{1,2,3},{4,5,6},{7,8,9},{10,11,12})
=IF(ISERROR(Chon),SUM($B$2:$B$36),SUMPRODUCT((MONTH($A$2:$A$36)=Chon)*$B$2:$B$36))