PhD Qualifier January 2005 May 2010 May 2005 July 2010 January 2006 May 2011 May 2006 July 2011 January 2007 May 2012 July 2007 July 2012 May 2008 May 2013 July 2008 July 2013 May 2009 May 2014 July 2009 July 2014