Solr doesnt return answer when searching numbers

[Mysurf Mail]

I am querying using

http://...:8983/solr/vault/select?q="design test"&fl=PackageName

I get 3 result:

   - design test
   - design test 2013
   - design test for jobs

Now when I query using q="test for jobs"
-> I get only "design test for jobs"

But when I query using q = 2013

http://...:8983/solr/vault/select?q=2013&fl=PackageName

I get no result. Why doesnt it return an answer when I query with numbers?

In schema xml

 <field name="PackageName" type="text_en" indexed="true" stored="true"
required="true"/>