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Table representation of search results timeline featuring number of search results per year.
Year
Number of Results
1977
1
1978
3
1980
8
1981
7
1982
9
1983
31
1984
36
1985
51
1986
45
1987
46
1988
67
1989
38
1990
62
1991
41
1992
49
1993
47
1994
46
1995
50
1996
42
1997
36
1998
38
1999
38
2000
35
2001
41
2002
27
2003
29
2004
32
2005
36
2006
39
2007
29
2008
29
2009
35
2010
24
2011
19
2012
21
2013
11
2014
9
2015
9
2016
9
2017
10
2018
12
2019
3
2020
4
2021
5
2022
2
2023
3
2024
0
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AMA
APA
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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