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 | 2007 | 3 |
| Non-citable documents | 2008 | 9 |
| Non-citable documents | 2009 | 15 |
| Non-citable documents | 2010 | 18 |
| Non-citable documents | 2011 | 14 |
| Non-citable documents | 2012 | 12 |
| Non-citable documents | 2013 | 12 |
| Non-citable documents | 2014 | 14 |
| Non-citable documents | 2015 | 12 |
| Non-citable documents | 2016 | 17 |
| Citable documents | 2007 | 63 |
| Citable documents | 2008 | 143 |
| Citable documents | 2009 | 229 |
| Citable documents | 2010 | 239 |
| Citable documents | 2011 | 180 |
| Citable documents | 2012 | 134 |
| Citable documents | 2013 | 112 |
| Citable documents | 2014 | 132 |
| Citable documents | 2015 | 132 |
| Citable documents | 2016 | 212 |