| E-Circulars | CSN Circulars | 
| 1987 - Circulars 1 to 107. |  | 
| 1988 - Circulars 108 to 230. |  | 
| 1989 - Circulars 234 to 376. |  | 
| 1990 - Circulars 377 to 471. |  | 
| 1991 - Circulars 472 to 593. |  | 
| 1992 - Circulars 594 to 697. |  | 
| 1993 - Circulars 698 to 803. |  | 
| 1994 - Circulars 804 to 912. |  | 
| 1995 - Circulars 913 to 1029. |  | 
| 1996 - Circulars 1030 to 1154. |  | 
| 1997 - Circulars 1155 to 1261. |  | 
| 1998 - Circulars 1262 to 1370. |  | 
| 1999 - Circulars 1371 to 1483. |  | 
| 2000 - Circulars 1490 to 1596. |  | 
| 2001 - Circulars 1597 to 1729 | 2001 - CSN 100 to 104 | 
| 2002 - Circulars 1730 to 1840 | 2002 - CSN 105 to 113 | 
| 2003 - Circulars 1841 to 1957 | 2003 - CSN 114 to 118 | 
| 2004 - Circulars 1958 to 2072 |  | 
| 2005 - Circulars 2073 to 2185 | 2005 - CSN 119 to 121 | 
| 2006 - Circulars 2186 to 2296 | 2006 - CSN 122 to 123 | 
| 2007 - Circulars 2297 to 2408 | 2007 - CSN 124 to 127 | 
| 2008 - Circulars 2409 to 2518 | - | 
| 2009 - Circulars 2519 to 2611 | - | 
| 2010 - Circulars 2612 to 2701 | - | 
| 2011 - Circulars 2702 to 2790 | - | 
| 2012 - Circulars 2791 to 2886 | - | 
| 2013 - Circulars 2887 to 2971 | - | 
| 2014 - Circulars 2972 to 3051 | - | 
| 2015 - Circulars 3052 to 3134 | - | 
| 2016 - Circulars 3135 to 3229 | - |