Moving sum in SQL server 2008 R2 - sql-server

Question

EDIT: the server I'm working on is 2008 R2 but my client is 2012...
I'm trying to create a conditionnal sum based on the month I'm in backing up to one year ago.
Here is the data I have:
Month Location Quantity1 Quantity2
200501 2072 46 42
200502 2072 53 51
200503 2072 141 132
200504 2072 134 129
200505 2072 75 72
200506 2072 75 74
200507 2072 77 72
200508 2072 56 52
200509 2072 58 54
200510 2072 59 52
200511 2072 71 69
200512 2072 48 46
200601 2072 62 55
200602 2072 209 197
200603 2072 143 138
200604 2072 78 67
200605 2072 95 86
200606 2072 78 73
200607 2072 80 73
200608 2072 68 62
200609 2072 54 46
200610 2072 52 49
200611 2072 50 50
200612 2072 28 27
so, what I would like as an output is something like this:
for the first month(200501) only it can be in the total as there were no records prior to it, up to 200512 it would be between the starting month (200501) and the month in question. Once it goes to 200601, it has to be a sum between 200502 and 200601.
I did the mannual calculations to help the validation process, so here they are:
Month Location SumQty1 SumQty2
200501 2072 46 42
200502 2072 99 93
200503 2072 240 225
200504 2072 374 354
200505 2072 449 426
200506 2072 524 500
200507 2072 601 572
200508 2072 657 624
200509 2072 715 678
200510 2072 774 730
200511 2072 845 799
200512 2072 893 845
200601 2072 909 858
200602 2072 1065 1004
200603 2072 1067 1010
200604 2072 1011 948
200605 2072 1031 962
200606 2072 1034 961
200607 2072 1037 962
200608 2072 1049 972
200609 2072 1045 964
200610 2072 1038 961
200611 2072 1017 942
200612 2072 997 923
Thank you for your time!

Answer 1

You can join the table to itself to get all dates that need to be added:
SELECT t1.Month ,
t1.Location ,
SUM(t2.Quantity1) AS SumQty1 ,
SUM(t2.Quantity2) AS SumQty2
FROM dbname.schemaname.tablename t1
INNER JOIN dbname.schemaname.tablename t2 ON t2.month >= t1.month - 99
AND t2.month <= t1.month
GROUP BY t1.month ,
t1.location

Answer 2

Try windowing functions (http://msdn.microsoft.com/en-GB/library/ms189461.aspx):
SELECT Month, Location,
SUM(Quantity1)
OVER (PARTITION BY Location ORDER BY Month ROWS 11 preceding) as SumQty1,
SUM(Quantity2)
OVER (PARTITION BY Location ORDER BY Month ROWS 11 preceding) as SumQty2
FROM
(SELECT 200501 as Month, 2072 as Location, 46 as Quantity1, 42 as Quantity2
UNION SELECT 200502, 2072, 53, 51
UNION SELECT 200503, 2072, 141, 132
...) as t;
Although note that this will only work if there are no missing months.