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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 |
|---|---|
| 1957 | 1 |
| 1962 | 2 |
| 1963 | 1 |
| 1969 | 2 |
| 1970 | 1 |
| 1971 | 2 |
| 1972 | 2 |
| 1974 | 2 |
| 1975 | 2 |
| 1977 | 1 |
| 1991 | 1 |
| 2004 | 1 |
| 2005 | 2 |
| 2006 | 1 |
| 2007 | 1 |
| 2008 | 2 |
| 2009 | 2 |
| 2010 | 3 |
| 2011 | 2 |
| 2012 | 2 |
| 2013 | 2 |
| 2014 | 3 |
| 2015 | 2 |
| 2017 | 3 |
| 2018 | 3 |
| 2019 | 2 |
| 2020 | 2 |
| 2021 | 1 |
| 2024 | 1 |
| 2025 | 0 |