Count rows in-between the one's

[FryGirl]

Using column A, how can I count the values in-between each one in column A and produce the results in column B?

Comal Corner.xlsm
	A	B
1	FT	Count
2	1	1
3	1	1
4	1	2
5	2
6	1	2
7	2
8	1	2
9	2
10	1	2
11	2
12	1	2
13	2
14	1	2
15	2
16	1	2
17	3
18	1	2
19	2
20	1	1
21	1	1
22	1	3
23	2
24	3
25	1	3
26	2
27	3
28	1	4
29	2
30	3
31	3
Sheet2

 

[Fluff]

How about

Fluff.xlsm
	A	B
1	FT	Count
2	1	1
3	1	1
4	1	2
5	2
6	1	2
7	2
8	1	2
9	2
10	1	2
11	2
12	1	2
13	2
14	1	2
15	2
16	1	2
17	3
18	1	2
19	2
20	1	1
21	1	1
22	1	3
23	2
24	3
25	1	3
26	2
27	3
28	1	4
29	2
30	3
31	3
Master

Cell Formulas
Range	Formula
B2:B31	B2	=IF(A2=1,IFNA(XMATCH(1,A3:A100),LOOKUP(2,1/(A3:A100<>""),ROW(A3:A100))-ROW()+1),"")

 

[Fluff]

Or slightly shorter

=IF(A2=1,IFNA(XMATCH(1,A3:A100),XMATCH("?",A2:A100&"",2,-1)),"")

 

[FryGirl]

Thank you Fluff. Works great!

 

[Fluff]

You're welcome & thanks for the feedback.