Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation

Search Page

Filters

My NCBI Filters

Results by year

Table representation of search results timeline featuring number of search results per year.

Year Number of Results
1949 3
1951 3
1952 6
1962 1
1965 11
1966 1
1967 11
1968 17
1969 13
1970 12
1971 17
1972 10
1973 3
1974 11
1975 11
1976 11
1977 12
1978 7
1979 10
1980 9
1981 15
1982 12
1983 17
1984 13
1985 21
1986 13
1987 19
1988 27
1989 28
1990 36
1991 37
1992 37
1993 39
1994 41
1995 103
1996 209
1997 222
1998 261
1999 226
2000 213
2001 224
2002 224
2003 220
2004 259
2005 283
2006 322
2007 345
2008 354
2009 454
2010 408
2011 421
2012 421
2013 406
2014 477
2015 449
2016 453
2017 466
2018 488
2019 393
2020 252
2021 122
2022 18
2023 4
2024 1

Text availability

Article attribute

Article type

Publication date

Search Results

8,477 results

Results by year

Filters applied: . Clear all
Page 1
8,477 results