1993-E

1994-F

1995-G

1996-H

1997-J

1998-K

1999-L

2000-M

2001-N

2002-P

2003-R

2004-S

2005-T

2006-V

2007-W

2008-X

2009-Y

2010-Z

2011-A

2012-B

2013-C

2014-D

The letters I, O, Q and U are not used.