Volumes 1-25
| Volume number | Dates covered |
|---|---|
| 1 | December 1972 - February 1974 |
| 2 | February 1974 - January 1975 |
| 3 | January 1975 - December 1975 |
| 4 | January 1976 - December 1976 |
| 5 | January 1977 - December 1977 |
| 6 | January 1978 - January 1979 |
| 7 | January 1979 - June 1979 |
| 8 | June 1979 - December 1979 |
| 9 | January 1980 - May 1980 |
| 10 | June 1980 - December 1980 |
| 11 | December 1980 - May 1981 |
| 12 | June 1981 - December 1981 |
| 13 | January 1982 - June 1982 |
| 14 | June 1982 - December 1982 |
| 15 | December 1982 - May 1983 |
| 16 | May 1983 - October 1983 |
| 17 | October 1983 - April 1984 |
| 18 | April 1984 - November 1984 |
| 19 | November 1984 - May 1985 |
| 20 | May 1985 - September 1985 |
| 21 | October 1985 - April 1986 |
| 22 | April 1986 - October 1986 |
| 23 | October 1986 - April 1987 |
| 24 | April 1987 - October 1987 |
| 25 | October 1987 - May 1988 |
Volumes 26-50
| Volume number | Dates covered |
|---|---|
| 26 | May 1988 - February 1989 |
| 27 | February 1989 - November 1989 |
| 28 | November 1989 - July 1990 |
| 29 | July 1990 - January 1991 |
| 30 | January 1991 - July 1991 |
| 31 | July 1991 - January 1992 |
| 32 | January 1992 - July 1992 |
| 33 | July 1992 - January 1993 |
| 34 | January 1993 - July 1993 |
| 35 | July 1993 - January 1994 |
| 36 | January 1994 - July 1994 |
| 37 | July 1994 - January 1995 |
| 38 | January 1995 - July 1995 |
| 39 | July 1995 - January 1996 |
| 40 | January 1996 - July 1996 |
| 41 | July 1996 - December 1996 |
| 42 | January 1997 - June 1997 |
| 43 | June 1997 - November 1997 |
| 44 | November 1997 - May 1998 |
| 45 | May 1998 - December 1998 |
| 46 | December 1998 - May 1999 |
| 47 | May 1999 - September 1999 |
| 48 | September 1999 - March 2000 |
| 49 | March 2000 - August 2000 |
| 50 | August 2000 - February 2001 |
Volumes 51-75
| Volume number | Dates covered |
|---|---|
| 51 | February 2001 - June 2001 |
| 52 | June 2001 - October 2001 |
| 53 | October 2001 - February 2002 |
| 54 | February 2002 - May 2002 |
| 55 | May 2002 - September 2002 |
| 56 | September 2002 - December 2002 |
| 57 | January 2003 - April 2003 |
| 58 | May 2003 - August 2003 |
| 59 | August 2003 - November 2003 |
| 60 | November 2003 - April 2004 |
| 61 | April 2004 - September 2004 |
| 62 | September 2004 - February 2005 |
| 63 | February 2005 - July 2005 |
| 64 | July 2005 - October 2005 |
| 65 | October 2005 - April 2006 |
| 66 | April 2006 - July 2006 |
| 67 | July 2006 - December 2006 |
| 68 | December 2006 - May 2007 |
| 69 | May 2007 - August 2007 |
| 70 | August 2007 - December 2007 |
| 71 | December 2007 - June 2008 |
| 72 | June 2008 - October 2008 |
| 73 | October 2008 - March 2009 |
| 74 | March 2009 - August 2009 |
| 75 | August 2009 - December 2009 |
Volumes 76-90
| Volume number | Dates covered |
|---|---|
| 76 | December 2009 - June 2010 |
| 77 | June 2010 - September 2010 |
| 78 | September 2010 - March 2011 |
| 79 | March 2011 - July 2011 |
| 80 | July 2011 - November 2011 |
| 81 | December 2011 - June 2012 |
| 82 | June 2012 - December 2012 |
| 83 | December 2012 - July 2013 |
| 84 | July 2013 - February 2014 |
| 85 | February 2014 - June 2014 |
| 86 | July 2014 - January 2015 |
| 87 | January 2015 - August 2015 |
| 88 | August 2015 - January 2016 |
| 89 | January 2016 - August 2016 |
| 90 | August 2016 - January 2017 |