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MEDLINE® Citation Counts by Year of Publication
(as of January 2022)*

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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
2021* 774,026 273,946 35%
2020 986,012 367,821 37%
2019 903,184 347,206 38%
2018 866,985 342,977 40%
2017 848,833 342,624 40%
2016 862,858 349,043 40%
2015 878,407 365,583 42%
2014 871,026 367,863 42%
2013 854,128 364,401 43%
2012 811,157 348,047 43%
2011 769,279 329,766 43%
2010 735,005 315,000 43%
2009 707,726 305,749 43%
2008 685,932 299,021 44%
2007 657,649 287,371 44%
2006 634,565 281,561 44%
2005 609,839 273,560 45%
2004 579,041 260,187 45%
2003 549,304 248,990 45%
2002 521,684 236,507 45%
2001 505,770 231,178 46%
2000 485,493 222,014 46%
1999 459,801 210,640 46%
1998 446,844 203,719 46%
1997 432,077 198,250 46%
1996 421,840 192,775 46%
1995 416,454 191,228 46%
1994 407,308 185,697 46%
1993 398,107 179,116 45%
1992 391,789 173,628 44%
1991 388,767 168,185 43%
1990 388,120 163,582 42%
1989 381,394 156,676 41%
1988 365,609 150,064 41%
1987 347,999 141,197 41%
1986 330,454 133,546 40%
1985 318,108 126,898 40%
1984 307,931 122,728 40%
1983 299,016 118,317 40%
1982 285,221 112,349 40%
1981 274,481 106,498 39%
1980 272,538 104,574 38%
1979 274,279 103,563 38%
1978 265,555 96,956 37%
1977 255,745 91,641 36%
1976 249,180 87,133 35%
1975 244,105 82,943 34%
1974 229,807 77,314 34%
1973 225,870 74,124 33%
1972 222,237 69,629 31%
1971 216,614 65,940 30%
1970 211,330 63,852 30%
1969 210,436 63,525 30%
1968 203,701 60,743 30%
1967 186,843 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 26,939,446 11,047,630 41%
Totals*** 28,727,313 NA NA

 

*Derived from the 2022 MEDLINE/PubMed Baseline produced in January 2022.

**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 27, 2022