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 | 2006 | 2 |
| Non-citable documents | 2007 | 2 |
| Non-citable documents | 2008 | 3 |
| Non-citable documents | 2009 | 3 |
| Non-citable documents | 2010 | 3 |
| Non-citable documents | 2011 | 2 |
| Non-citable documents | 2012 | 1 |
| Non-citable documents | 2013 | 1 |
| Non-citable documents | 2014 | 1 |
| Non-citable documents | 2015 | 1 |
| Non-citable documents | 2016 | 1 |
| Citable documents | 2006 | 16 |
| Citable documents | 2007 | 33 |
| Citable documents | 2008 | 57 |
| Citable documents | 2009 | 69 |
| Citable documents | 2010 | 83 |
| Citable documents | 2011 | 83 |
| Citable documents | 2012 | 84 |
| Citable documents | 2013 | 81 |
| Citable documents | 2014 | 87 |
| Citable documents | 2015 | 90 |
| Citable documents | 2016 | 87 |