Drag Rank Function ?

Does anyone know of a way to click and drag the Rank function ?

Please see below attached example...........

So I have a large spreadsheet that has groupings of data, some groups are only two rows, however some are up to 20 rows. Each group has a blank row that separates it from the next group. For each group I have to rank the values, and to do this I have to copy and paste a rank function. What I would like to do is just click and drag the functions to any new rows I insert into the spreadsheet, is there any way to do this ?

units value rank

5 38 1
5 85 3
5 87 4
5 82 2
5 95 5

9 2 1
9 68 8
9 30 4
9 23 3
9 31 6
9 92 9
9 67 7
9 30 4
9 6 2

4 91 4
4 21 3
4 3 1
4 18 2

6 59 3
6 80 6
6 71 5
6 70 4
6 10 1
6 12 2

That worked fine, thankyou !

Or try:

=IF(A2="","",COUNTIFS(A:A,A2,B:B,"<"&B2)+1)