Year When Each Episode Was Written
Note: Most episodes before No. 300 were subsequently revised (as noted at the end of the original episode.) When this has been done, the later episode should be used in place of the original.
1988 -- Episodes 66-204
1989 -- Episodes 205-355
1990 -- Episodes 356-501
1991 -- Episodes 502-640
1992 -- Episodes 641-772
1993 -- Episodes 773-895
1994 -- Episodes 896-988
1995 -- Episodes 989-1072
1996 -- Episodes 1073-1194
1997 -- Episodes 1195-1282
1998 -- Episodes 1283-1385
2000 -- Episodes 1506-1586
2001 -- Episodes 1587-1671
2002 -- Episodes 1672-1760
2003 -- Episodes 1761-1869
2004 -- Episodes 1870-1960
2005 -- Episodes 1962-2044
2006 -- Episodes 2045-2174
2007 -- Episodes 2175-2306
2008 -- Episodes 2307-2447
2009 -- Episodes 2448-2563
2010 -- Episodes 2564-2669
2011 -- Episodes 2670-...