I am very new to using XML and making my first XML Schema. I want to write something in XML schema that will allow me to read a matrix. For example, I want to have a matrix that looks like this:

HTML Code:
<matrix >
  <row >2.1 3.4</row>
  <row >100.5 6.7</row>
  <row >-2.76 5.9</row>
  <row >-7.53 -30.21</row>
All the values in this matrix will be decimals (no limits) and there will only be 2 values in each row. In addition, there is no restriction on the number of rows so when I am reading the XML, I want to continue reading until the last row is read. How will I write an XML schema that will allow me to verify this?
So far I have got something like:

<xs:element name="row" type="valuelist">
<xs:simpleType name="valuelist">
  <xs:list itemType="xs:decimal"/>

I think this will allow me to read a row, but it doesn't let me place a limit of only 2 values in a row. And how would I read all the rows in a matrix?

Thanks for your help!