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Table representation of search results timeline featuring number of search results per year.
Year
Number of Results
1951
2
1952
4
1953
2
1954
1
1955
4
1956
5
1957
8
1958
4
1959
5
1964
4
1965
21
1966
45
1967
46
1968
71
1969
61
1970
63
1971
76
1972
98
1973
93
1974
86
1975
93
1976
72
1977
94
1978
78
1979
96
1980
86
1981
114
1982
121
1983
138
1984
155
1985
149
1986
139
1987
167
1988
174
1989
189
1990
201
1991
187
1992
185
1993
195
1994
220
1995
244
1996
219
1997
244
1998
256
1999
297
2000
257
2001
289
2002
314
2003
326
2004
341
2005
336
2006
366
2007
384
2008
469
2009
504
2010
480
2011
536
2012
576
2013
556
2014
602
2015
584
2016
602
2017
585
2018
551
2019
547
2020
526
2021
402
2022
47
2023
10
2024
115
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AMA
APA
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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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