Notes:
4th softcover edition: March 2001; 5th - 6th softcover edition: (2001); 7th: September 2001; 8th: 2002; 10th: March 2003; 11th: May 2004; 12th: January 2005; 13th: December 2005; 14th: February 2007 (9.95 USD, 14.95 CAD); 15th: January 2008; 16th: January 2009; 17th: 2010 (11.95 USD); 18th: November 2011; 19th: 2013; 21st: February 2015; 22nd: ?; 23rd: November 2017