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 | 0 |
| Non-citable documents | 2007 | 2 |
| Non-citable documents | 2008 | 9 |
| Non-citable documents | 2009 | 23 |
| Non-citable documents | 2010 | 26 |
| Non-citable documents | 2011 | 32 |
| Non-citable documents | 2012 | 33 |
| Non-citable documents | 2013 | 30 |
| Non-citable documents | 2014 | 19 |
| Non-citable documents | 2015 | 4 |
| Non-citable documents | 2016 | 2 |
| Non-citable documents | 2017 | 0 |
| Citable documents | 2006 | 0 |
| Citable documents | 2007 | 52 |
| Citable documents | 2008 | 99 |
| Citable documents | 2009 | 150 |
| Citable documents | 2010 | 152 |
| Citable documents | 2011 | 154 |
| Citable documents | 2012 | 148 |
| Citable documents | 2013 | 110 |
| Citable documents | 2014 | 87 |
| Citable documents | 2015 | 64 |
| Citable documents | 2016 | 48 |
| Citable documents | 2017 | 22 |