| Created | Total EC count | Orphan EC count |
|---|---|---|
| 1961 | 634 | 67 |
| 1965 | 172 | 34 |
| 1972 | 843 | 225 |
| 1975 | 1 | 0 |
| 1976 | 226 | 63 |
| 1978 | 111 | 33 |
| 1980 | 6 | 2 |
| 1981 | 43 | 4 |
| 1982 | 19 | 2 |
| 1983 | 68 | 18 |
| 1984 | 266 | 70 |
| 1986 | 95 | 35 |
| 1989 | 247 | 101 |
| 1990 | 95 | 41 |
| 1992 | 276 | 80 |
| 1993 | 20 | 1 |
| 1995 | 17 | 2 |
| 1996 | 11 | 0 |
| 1997 | 10 | 0 |
| 1999 | 135 | 28 |
| 2000 | 156 | 31 |
| 2001 | 76 | 8 |
| 2002 | 89 | 10 |
| 2003 | 86 | 4 |
| 2004 | 61 | 11 |
| 2005 | 92 | 5 |
| 2006 | 94 | 6 |
| 2007 | 59 | 6 |
| 2008 | 68 | 8 |
| 2009 | 75 | 6 |
| 2010 | 162 | 5 |
| 2011 | 364 | 19 |
| 2012 | 305 | 14 |
| 2013 | 278 | 16 |
| 2014 | 231 | 14 |
| 2015 | 177 | 16 |
| 2016 | 174 | 23 |
| 2017 | 220 | 14 |
| 2018 | 182 | 26 |
| 2019 | 164 | 28 |
| 2020 | 89 | 21 |
| 2021 | 108 | 34 |
| 2022 | 100 | 32 |
| 2023 | 50 | 26 |
| 2024 | 120 | 85 |
| 20022 | 1 | 0 |