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
1964 2
1965 8
1966 22
1967 59
1968 46
1970 1
1971 2
1972 1
1974 2
1976 1
1977 3
1979 3
1980 2
1981 1
1982 8
1983 3
1984 9
1985 3
1986 6
1987 7
1988 23
1989 189
1990 844
1991 1137
1992 1489
1993 1513
1994 1886
1995 2098
1996 2252
1997 2352
1998 2853
1999 2784
2000 3131
2001 3411
2002 3872
2003 4874
2004 4219
2005 2961
2006 2677
2007 2629
2008 2521
2009 2554
2010 2526
2011 2584
2012 2659
2013 2758
2014 2601
2015 2559
2016 2525
2017 2494
2018 2479
2019 2535
2020 2206
2021 1680
2022 769
2023 576
2024 219

Text availability

Article attribute

Article type

Publication date

Search Results

78,624 results

Results by year

Filters applied: . Clear all
Page 1
78,624 results
You have reached the last available page of results. Please see the User Guide for more information.