Number of segments

[Michael Long]

I'm running solr 4.0. I'm noticing my segments are staying in the 30+ 
range, even though I have these settings:

<indexConfig>
<mergePolicy class="org.apache.lucene.index.TieredMergePolicy">
    <int name="segmentsPerTier">10</int>
    <int name="maxMergeAtOnce">10</int>
    <int name="maxMergeAtOnceExplicit">10</int>
</mergePolicy>
<useCompoundFile>false</useCompoundFile>
Can anyone give me some advice on what I should change or check?