Why does verbose output not equal dim of dfm?

```
> presDfm <- dfm(inaugCorpus)
Creating a dfm from a corpus ...
   ... lowercasing
   ... tokenizing
   ... indexing documents: 57 documents
   ... indexing features: 9,214 feature types
   ... created a 57 x 9215 sparse dfm
   ... complete. 
Elapsed time: 0.364 seconds.
```
