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Table representation of search results timeline featuring number of search results per year.
Year
Number of Results
1951
1
1952
7
1953
12
1954
16
1955
13
1956
16
1957
9
1958
17
1959
10
1960
13
1961
10
1962
13
1963
2
1964
1
1965
3
1966
144
1967
238
1968
261
1969
301
1970
264
1971
261
1972
269
1973
282
1974
248
1975
232
1976
193
1977
166
1978
130
1979
136
1980
137
1981
127
1982
134
1983
140
1984
204
1985
177
1986
200
1987
131
1988
160
1989
151
1990
161
1991
160
1992
112
1993
127
1994
114
1995
101
1996
82
1997
81
1998
79
1999
80
2000
75
2001
70
2002
60
2003
69
2004
58
2005
69
2006
68
2007
53
2008
62
2009
77
2010
50
2011
56
2012
64
2013
55
2014
71
2015
80
2016
65
2017
70
2018
57
2019
64
2020
48
2021
34
2022
19
2023
14
2024
22
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MLA
NLM
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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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