How many Diary of a Wimpy Kid books are there in 2013?

There were 8 Diary of a Wimpy Kid books in 2013.

Here's the list:

1. Diary of a Wimpy Kid (2007)

2. Rodrick Rules (2008)

3. The Last Straw (2009)

4. Dog Days (2009)

5. The Ugly Truth (2010)

6. Cabin Fever (2011)

7. The Third Wheel (2012)

8. Hard Luck (2013)