An Average of a Count erroneously returns integers and not decimals

Question

I have a table which holds sales information showing the invoice number and the branch (e.g. 'New York', 'Boston', etc..)  that sold the items. Each row represents a product on an invoice. I am trying to find out the average number of lines per invoice
for each branch. So my final result set might tell me that the 'New York' invoices had an average of 2.4 lines per invoice and the 'Boston' invoices had an average of 1.9 lines per invoice. Like this:
New York, 2.4
Boston, 1.9
I've first written a subquery that counts the number of lines for each BRANCH & INVOICE combination for any date after 1/1/2015. Then I've put a query around that subquery which averages this count by Branch. The problem is, the entire query is only
returning integers and not decimals. Why is this?
Note that I tried casting the data type to DECIMAL and FLOAT but still get the same results.
Here is the query:
Select t1.Branch, cast(avg(t1.Count) as numeric(10,2))
as Avg_Lines
from
(Select Branch, invoice, count(*) as Count
 from linprm
 where invdte>20150101
 group by Branch, invoice) t1
 group by t1.Branch

Answer 1

To expand Scott's answer:
Select t1.Branch, avg(cast(t1.Count as numeric(10,2)))
as Avg_Lines
from
(Select Branch, invoice, count(*) as Count
from linprm
where invdte>20150101
group by Branch, invoice) t1
group by t1.Branch
-- or
Select t1.Branch, cast(avg(t1.Count) as numeric(10,2))
as Avg_Lines
from
(Select Branch, invoice, cast(count(*) as numeric(10,2)) as Count
from linprm
where invdte>20150101
group by Branch, invoice) t1
group by t1.Branch
Russel Loski, MCT, MCSE Data Platform/Business Intelligence. Twitter: @sqlmovers; blog: www.sqlmovers.com