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 Custom Filters

Results by year

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

Year Number of Results
1966 6
1967 12
1968 6
1969 8
1970 14
1971 12
1972 12
1973 19
1974 16
1975 22
1976 10
1977 18
1978 31
1979 32
1980 26
1981 24
1982 39
1983 29
1984 71
1985 42
1986 44
1987 43
1988 54
1989 41
1990 64
1991 51
1992 57
1993 46
1994 56
1995 43
1996 67
1997 78
1998 53
1999 59
2000 89
2001 70
2002 107
2003 103
2004 115
2005 141
2006 185
2007 167
2008 223
2009 232
2010 290
2011 338
2012 376
2013 375
2014 371
2015 366
2016 431
2017 467
2018 447
2019 519
2020 449
2021 400
2022 68
2023 46
2024 549
2025 8

Publication date

Text availability

Article attribute

Article type

Additional filters

Article Language

Species

Sex

Age

Other

Search Results

7,339 results

Results by year

Filters applied: . Clear all
Page 1
7,339 results