Need Help with Array Formula

I am looking for an formula that will give me the average of the last 10 entries in a column.
I have tried the following formulas, but they are not giving me the correct average:
=AVERAGE(OFFSET(N$1,MAX(COUNT(N:N)-10,0),,10))
=INDEX(Sheet2!$A$1:$E$5,MATCH($A1,Sheet2!$A$1:$A$5,0),COLUMN())

Any help would be appreciated.