United States National Library of Medicine National Institutes of Health

MEDLINE® Citation Counts by Year of Publication

MEDLINE consists of completed citations indexed with MeSH® (Medical Subject Headings®).

Year of publication Total # Citations # Citations from Journals Published in US % Citations from Journals Published in US
2008* 565,311 267,711 47%
2007 709,539 313,301 44%
2006 685,052 303,974 44%
2005 643,040 290,481 45%
2004 592,457 272,723 46%
2003 556,203 260,465 47%
2002 525,754 246,449 47%
2001 507,239 239,592 47%
2000 486,445 229,765 47%
1999 457,483 217,012 47%
1998 446,709 211,419 47%
1997 431,560 205,463 48%
1996 421,820 200,055 47%
1995 416,485 198,012 48%
1994 407,290 191,675 47%
1993 397,984 184,937 46%
1992 391,716 179,291 46%
1991 388,830 173,932 45%
1990 388,155 169,353 44%
1989 381,441 162,344 43%
1988 365,642 155,184 42%
1987 348,009 146,116 42%
1986 330,461 138,697 42%
1985 318,091 131,696 41%
1984 307,916 127,282 41%
1983 299,045 122,827 41%
1982 285,262 116,178 41%
1981 274,391 109,691 40%
1980 272,449 107,566 39%
1979 274,239 106,891 39%
1978 265,541 101,085 38%
1977 255,760 95,913 38%
1976 249,331 91,636 37%
1975 244,330 87,296 36%
1974 230,194 80,847 35%
1973 226,468 77,485 34%
1972 222,561 72,790 33%
1971 217,928 70,039 32%
1970 212,761 67,161 32%
1969 210,958 66,964 32%
1968 204,005 63,775 31%
1967 186,962 58,554 31%
1966 175,057 55,506 32%
1965** 165,223 50,562 31%
1964** 141,915 42,610 30%
1963** 130,247 NA NA
1962** 108,823 NA NA
1961** 97,313 NA NA
1960** 91,312 NA NA
1959** 83,677 NA NA
1958** 75,138 NA NA
1957** 77,761 NA NA
1956** 74,445 NA NA
1955** 75,615 NA NA
1954** 74,107 NA NA
1953** 79,095 NA NA
1952** 82,369 NA NA
1951** 85,406 NA NA
1950** 74,028 NA NA
1949** 38,439 NA NA
1948** 26,355 NA NA
Pre-1948** 33,196 NA NA
1964-2008* Subtotals 16,085,012 6,862,305 43%
Totals*** 17,359,142 ——— ———


*Searches were done in PubMed® on February 3, 2009. Publication year 2008 is not yet complete.

**As of December 2006, OLDMEDLINE subset citations that have all of their original subject terms mapped to current MeSH are included in MEDLINE. There are more citations in PubMed with these older publication dates; some are OLDMEDLINE status, but some are PubMed status or "as supplied by publisher" status.

***PubMed includes both the print and electronic publication dates in a publication date search; therefore, citations may be counted under more than one year. The totals do not include these duplicates.

Notes:
- Any search repeated on a later day may yield different results (typically higher numbers, as NLM may have processed more completed citations for various reasons, e.g., time lag in receipt, or a new journal for indexing going back to volume 1, or data from back issues such as those deposited in PubMed Central, or from other sources).
- Counts are limited to the MEDLINE subset [sb] of PubMed and do not include out-of-scope citations. To search PubMed for MEDLINE excluding OLDMEDLINE subset citations, add NOT jsubsetom to your search.
- Country of publication means the country where the journal was published. These data are available for the OLDMEDLINE subset only for the years 1964-65.

Last reviewed: 25 March 2009
Last updated: 25 March 2009
First published: 27 May 2003
Metadata| Permanence level: Permanence Not Guaranteed