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The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
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The https:// ensures that you are connecting to the
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and transmitted securely.
Table representation of search results timeline featuring number of search results per year.
| Year | Number of Results |
|---|---|
| 1961 | 2 |
| 1964 | 1 |
| 1969 | 1 |
| 1974 | 1 |
| 1975 | 1 |
| 1980 | 2 |
| 1983 | 1 |
| 1989 | 1 |
| 1990 | 2 |
| 1991 | 1 |
| 1993 | 2 |
| 1994 | 4 |
| 1995 | 5 |
| 1996 | 1 |
| 1997 | 1 |
| 1998 | 2 |
| 2001 | 2 |
| 2002 | 3 |
| 2003 | 1 |
| 2006 | 2 |
| 2007 | 1 |
| 2008 | 5 |
| 2009 | 1 |
| 2010 | 1 |
| 2011 | 1 |
| 2012 | 5 |
| 2013 | 5 |
| 2014 | 4 |
| 2015 | 4 |
| 2016 | 3 |
| 2017 | 3 |
| 2018 | 3 |
| 2019 | 4 |
| 2020 | 3 |
| 2021 | 3 |
| 2022 | 2 |
| 2023 | 1 |