Not every article in a journal is considered primary research and therefore "citable", this chart shows the ratio of a journal's articles including substantial research (research articles, conference papers and reviews) in three year windows vs. those documents other than research articles, reviews and conference papers.
| Documents | Year | Value |
| Non-citable documents | 1999 | 0 |
| Non-citable documents | 2000 | 0 |
| Non-citable documents | 2001 | 0 |
| Non-citable documents | 2002 | 0 |
| Non-citable documents | 2003 | 3 |
| Non-citable documents | 2004 | 3 |
| Non-citable documents | 2005 | 3 |
| Non-citable documents | 2006 | 0 |
| Non-citable documents | 2007 | 0 |
| Non-citable documents | 2008 | 3 |
| Non-citable documents | 2009 | 5 |
| Non-citable documents | 2010 | 6 |
| Non-citable documents | 2011 | 4 |
| Non-citable documents | 2012 | 2 |
| Non-citable documents | 2013 | 1 |
| Non-citable documents | 2014 | 2 |
| Non-citable documents | 2015 | 4 |
| Non-citable documents | 2016 | 5 |
| Non-citable documents | 2017 | 3 |
| Non-citable documents | 2018 | 2 |
| Non-citable documents | 2019 | 1 |
| Non-citable documents | 2020 | 1 |
| Non-citable documents | 2021 | 0 |
| Citable documents | 1999 | 178 |
| Citable documents | 2000 | 175 |
| Citable documents | 2001 | 176 |
| Citable documents | 2002 | 176 |
| Citable documents | 2003 | 185 |
| Citable documents | 2004 | 196 |
| Citable documents | 2005 | 202 |
| Citable documents | 2006 | 194 |
| Citable documents | 2007 | 187 |
| Citable documents | 2008 | 188 |
| Citable documents | 2009 | 219 |
| Citable documents | 2010 | 267 |
| Citable documents | 2011 | 322 |
| Citable documents | 2012 | 329 |
| Citable documents | 2013 | 331 |
| Citable documents | 2014 | 376 |
| Citable documents | 2015 | 365 |
| Citable documents | 2016 | 364 |
| Citable documents | 2017 | 311 |
| Citable documents | 2018 | 313 |
| Citable documents | 2019 | 280 |
| Citable documents | 2020 | 235 |
| Citable documents | 2021 | 208 |