When was the Percy Jackson series published?

The Percy Jackson & the Olympians series was published between 2005 and 2009.

Here's a breakdown:

* The Lightning Thief: Published in 2005

* The Sea of Monsters: Published in 2006

* The Titan's Curse: Published in 2007

* The Battle of the Labyrinth: Published in 2008

* The Last Olympian: Published in 2009