Fix bug displaying total navigation time.

Before: 
![Screen Shot 2013-03-18 at 12 53 48 AM](https://f.cloud.github.com/assets/2035/269148/7de6b23c-8f7f-11e2-9945-bfd5579469db.png)

After:
![Screen Shot 2013-03-18 at 12 53 55 AM](https://f.cloud.github.com/assets/2035/269149/86aee0f6-8f7f-11e2-8cc3-26a441fa6c1b.png)