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MEDLINE® Citation Counts by Year of Publication
(as of January 2021)*

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

Year of Publication Total # Citations # Citations Published in US %s Citations Published in US
2020* 362,528 138,112 38%
2019 898,145 345,923 39%
2018 866,977 343,605 40%
2017 848,776 343,947 41%
2016 862,829 351,138 41%
2015 878,403 367,373 43%
2014 871,023 370,119 42%
2013 854,130 365,771 43%
2012 811,156 349,243 43%
2011 769,278 330,630 43%
2010 735,005 315,629 43%
2009 707,726 306,508 43%
2008 685,934 299,219 44%
2007 657,649 287,685 44%
2006 634,565 281,823 44%
2005 609,839 273,746 45%
2004 579,041 260,454 45%
2003 549,304 249,322 45%
2002 521,684 236,849 45%
2001 505,770 231,417 46%
2000 485,494 222,372 46%
1999 459,801 210,928 46%
1998 446,844 204,003 46%
1997 432,077 198,517 46%
1996 421,840 193,028 46%
1995 416,454 191,470 46%
1994 407,308 185,945 46%
1993 398,107 179,327 45%
1992 391,789 173,795 44%
1991 388,767 168,321 43%
1990 388,150 163,723 42%
1989 381,394 156,836 41%
1988 365,609 150,112 41%
1987 347,999 141,243 41%
1986 330,454 133,582 40%
1985 318,108 126,945 40%
1984 307,931 122,777 40%
1983 299,016 118,328 40%
1982 285,221 112,363 40%
1981 274,481 106,472 39%
1980 272,538 104,583 38%
1979 274,279 103,576 38%
1978 265,555 96,962 37%
1977 255,745 91,660 36%
1976 249,180 87,141 35%
1975 244,105 82,956 34%
1974 229,807 77,314 34%
1973 225,871 74,123 33%
1972 222,237 69,625 31%
1971 216,614 65,936 30%
1970 211,330 63,838 30%
1969 210,437 63,526 30%
1968 203,701 60,743 30%
1967 186,846 55,765 30%
1966 175,197 53,282 30%
1965 173,135 52,229 30%
1964 158,922 48,007 30%
1963** 137,734 NA NA
1962** 122,645 NA NA
1961** 117,003 NA NA
1960** 108,860 NA NA
1959** 107,786 NA NA
1958** 107,655 NA NA
1957** 109,811 NA NA
1956** 105,228 NA NA
1955** 106,759 NA NA
1954** 104,007 NA NA
1953** 107,678 NA NA
1952** 106,850 NA NA
1951** 102,578 NA NA
1950** 84,099 NA NA
1949** 60,931 NA NA
1948** 68,711 NA NA
1947** 62,869 NA NA
Pre-1947** 66,663 NA NA
1964-Present Subtotals 25,533,347 10,560,023 41%
Totals*** 27,321,214 NA NA

 

*Derived from the 2021 MEDLINE/PubMed Baseline produced in January 2021.

**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 PubMed status or "as supplied by publisher" status. As of the 2017 MEDLINE/PubMed baseline, all OLDMEDLINE subset citations were converted to MEDLINE status because every such citation was mapped to at least one current MeSH heading. In the future when NLM adds more OLDMEDLINE citations, there may be a period of time when the citations status equals OLDMEDLINE until NLM can map to current MeSH.

Notes:
  1. Typically a PubMed search will yield higher numbers, as NLM may have processed more completed citations since the baseline was produced 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. Also, PubMed includes both the print and electronic publication dates in a publication date search. Therefore, citations to articles published electronically and in print with 2 different publication dates will be retrieved in 2 different [dp] searches, thereby getting counted twice. For example, a paper published electronically in December 2013 and in print in January 2014 will be counted once in a 2013 [dp] search and again in a 2014 [dp] search.
  2. Counts are limited to the MEDLINE subset [sb] of PubMed and do not include out-of-scope citations.
    To search PubMed for the out-of-scope completed citations use: pubmednotmedline [sb]
    To search PubMed for MEDLINE excluding OLDMEDLINE subset citations, add NOT jsubsetom to your search; for example: 1965 [dp] AND medline [sb] NOT jsubsetom.
  3. 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: May 15, 2020