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
1961 2
1963 2
1964 7
1965 1
1966 2
1967 168
1968 264
1969 202
1970 137
1971 134
1972 186
1973 283
1974 312
1975 194
1976 185
1977 219
1978 312
1979 293
1980 422
1981 356
1982 411
1983 459
1984 452
1985 551
1986 506
1987 516
1988 549
1989 456
1990 451
1991 612
1992 575
1993 490
1994 616
1995 494
1996 577
1997 760
1998 842
1999 1122
2000 1301
2001 1114
2002 1042
2003 1172
2004 1390
2005 1555
2006 1707
2007 2002
2008 2104
2009 2451
2010 2471
2011 2369
2012 2365
2013 2516
2014 2311
2015 2072
2016 1867
2017 1675
2018 1546
2019 1367
2020 1080
2021 566
2022 300
2023 363
2024 281

Search Results

47,766 results

Results by year

Filters applied: . Clear all
Page 1
47,766 results
You have reached the last available page of results. Please see the User Guide for more information.