Sumif to last cell

I am keeping a betting spreadsheet and I have to keep updating my formulas when I add more bets. Is there a way that it will automatically change the formula so I don't have to edit it every time? My forumlas look like this:

{=SUM(IF((I3:I142="NFL")*(B3:B142="W"),C3:C142))}

So basically if I add bets and the last line of bets now goes to 145, how can I make it update it by itself?

Help is greatly appreciated. Thanks!