Sheets: Getting the slope of the 10 cells above current

I'd like a formula for Google Sheets, but I'm having trouble figuring it out.

Say I'm on B74, I want the equivalent of =SLOPE(B36:B63,A36:A63). However, I want something that will work even when I add a new row under 63. At which point, I want =SLOPE(B37:B64,A37:A64).

I used =AVERAGE(OFFSET(INDIRECT(ADDRESS(ROW(),COLUMN())),-38,,28)) works perfectly to get the average value within this range, but I can't figure out one for slope.