1983, Colorado
1988, Richmond
1991, Washington DC
1994, New York
1996, Minneapolis
1998, Charleston
2000, Philadelphia
2001, Baltimore
2004, Boston
2005, San Diego
2007, San Francisco
2009, Denison
2011, Minneapolis
2013, Los Angeles
2015, Toronto
2017, Cambridge, MA
2019, Edinburgh, Scotland
2022, Athens, Georgia
