I think this needs a legend to explain for those of us that forget the personnel numbering scheme.
The count is simple...the first number is the count of running backs...the second number is the number of tight ends.
Spelling it out with examples...
0 RB packages:
00... five WR
01... 4 WR 1 TE
02...3 WR, 2 TE
Other Receiver-heavy packages
10...4 WR, 1 RB
11... 3 WR, 1 TE, 1 RB
Heavier Packages:
12 = 2 WR, 2 TE, 1 RB
13= 1 RB, 3 TE, 1 WR
You don't see two Running backs in the backfield in the NFL anymore, but...
21 = 2 WR, 1 TE, 2 RB
22= 1 WR, 2 RB, 2 TE