XML Schemas

Hi,
I'm trying to build a schema, but I'm having 2 problems (both the same).

Bascially I want to define a list of "allowed numbers", e.g.,

201-205, 215-220, 340-354 etc.

I assumed that all I need to do was the following;

<xs:complexType name="LEA">
<xs:annotation>
<xs:documentation>List of valid LEAs</xs:documentation>
</xs:annotation>
<xs:choice>
<xs:element name="LEA201-203">
<xs:simpleType>
<xs:restriction base="xs:integer">
<xs:minInclusive value="201"/>
<xs:maxInclusive value="213"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
<xs:element name="LEA310-320">
<xs:simpleType>
<xs:restriction base="xs:integer">
<xs:minInclusive value="310"/>
<xs:maxInclusive value="320"/>
</xs:restriction>
</xs:simpleType>
</xs:element>

etc. (the rest is more of the list and is well formed).

Is that the right way to do it ?
I *could* just provide this list as a simple list with all the values (there are about 150), but my other list has 23000 so that's not really an option !

Cheers
Andy