Popularity in England and Wales
Numbers
| Declan (masculine) | |||
| Year | Rank | Percent Used | |
| 2023 | #388 | 0.034 | |
| 2022 | #381 | 0.036 | |
| 2021 | #390 | 0.035 | |
| 2020 | #368 | 0.038 | |
| 2019 | #388 | 0.034 | |
| 2018 | #399 | 0.032 | |
| 2017 | #314 | 0.046 | |
| 2016 | #294 | 0.047 | |
| 2015 | #245 | 0.061 | |
| 2014 | #250 | 0.061 | |
| 2013 | #198 | 0.078 | |
| 2012 | #175 | 0.091 | |
| 2011 | #149 | 0.107 | |
| 2010 | #133 | 0.121 | |
| 2009 | #136 | 0.120 | |
| 2008 | #123 | 0.125 | |
| 2007 | #126 | 0.123 | |
| 2006 | #122 | 0.129 | |
| 2005 | #108 | 0.155 | |
| 2004 | #92 | 0.185 | |
| 2003 | #92 | 0.190 | |
| 2002 | #89 | 0.194 | |
| 2001 | #81 | 0.233 | |
| 2000 | #66 | 0.258 | |
| 1999 | #73 | 0.242 | |
| 1998 | #85 | 0.203 | |
| 1997 | #69 | 0.286 | |
| 1996 | #83 | 0.204 | |
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