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Table representation of search results timeline featuring number of search results per year.
Year
Number of Results
1946
7
1947
8
1948
7
1949
6
1950
30
1951
27
1952
27
1953
40
1954
65
1955
88
1956
79
1957
90
1958
77
1959
77
1960
78
1961
82
1962
124
1963
105
1964
132
1965
129
1966
119
1967
154
1968
186
1969
210
1970
228
1971
250
1972
313
1973
304
1974
230
1975
311
1976
252
1977
231
1978
264
1979
230
1980
258
1981
253
1982
213
1983
257
1984
225
1985
238
1986
280
1987
269
1988
349
1989
309
1990
316
1991
328
1992
375
1993
429
1994
426
1995
410
1996
412
1997
376
1998
475
1999
443
2000
419
2001
391
2002
393
2003
378
2004
454
2005
382
2006
350
2007
365
2008
364
2009
355
2010
368
2011
399
2012
448
2013
498
2014
525
2015
462
2016
447
2017
523
2018
538
2019
433
2020
665
2021
607
2022
525
2023
523
2024
339
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MLA
NLM
21,155
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AMA
APA
MLA
NLM
Adaptive Clinical Trial
Address
Autobiography
Bibliography
Biography
Case Reports
Classical Article
Clinical Conference
Clinical Study
Clinical Trial Protocol
Clinical Trial, Phase I
Clinical Trial, Phase II
Clinical Trial, Phase III
Clinical Trial, Phase IV
Clinical Trial, Veterinary
Collected Work
Comment
Comparative Study
Congress
Consensus Development Conference
Consensus Development Conference, NIH
Controlled Clinical Trial
Corrected and Republished Article
Dataset
Dictionary
Directory
Duplicate Publication
Editorial
Electronic Supplementary Materials
English Abstract
Equivalence Trial
Evaluation Study
Expression of Concern
Festschrift
Government Publication
Guideline
Historical Article
Interactive Tutorial
Interview
Introductory Journal Article
Lecture
Legal Case
Legislation
Letter
Multicenter Study
News
Newspaper Article
Observational Study
Observational Study, Veterinary
Overall
Patient Education Handout
Periodical Index
Personal Narrative
Portrait
Practice Guideline
Pragmatic Clinical Trial
Preprint
Published Erratum
Randomized Controlled Trial, Veterinary
Research Support, American Recovery and Reinvestment Act
Research Support, N.I.H., Extramural
Research Support, N.I.H., Intramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Research Support, U.S. Gov't
Retracted Publication
Retraction of Publication
Scientific Integrity Review
Technical Report
Twin Study
Validation Study
Video-Audio Media
Webcast
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