Cell Reference Formula

[mwgr5]

My sheet has a year input.
The rest is basically an income statement.

I want to make a formula that sums from the first year to the last year. The last year would be the input year. So basically, I want the number of cells being summed to shrink or expand based on how this input year changes. Is there a way to do this?

Thanks.

[mwgr5]

Never mind, just remembered you can do this using the offset function.