XML defaulting ss:Type 4 all cells in a column, not ineach <data
 

I am creating an XML with many rows, report style. All cells in a given
column are always, numbers or strings.

Is there any way to default the ss:Type in <Data to the column? so the file
becomes substantially smaller?

Current:
<Cell<Data ss:Type="Number"30</Data</Cell
Wanter:
<Cell<Data30</Data</Cell

Getting the following error in the log when opening the file if I remove the
ss:Type="Number"

XML ERROR in Table
REASON: Missing Tag
FILE: C:\r7b.xml
GROUP: Cell
TAG: Data
ATTRIB: Type