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 | 2008 | 7 |
| Non-citable documents | 2009 | 14 |
| Non-citable documents | 2010 | 35 |
| Non-citable documents | 2011 | 49 |
| Non-citable documents | 2012 | 63 |
| Non-citable documents | 2013 | 75 |
| Non-citable documents | 2014 | 91 |
| Non-citable documents | 2015 | 107 |
| Non-citable documents | 2016 | 81 |
| Citable documents | 2008 | 126 |
| Citable documents | 2009 | 286 |
| Citable documents | 2010 | 462 |
| Citable documents | 2011 | 512 |
| Citable documents | 2012 | 546 |
| Citable documents | 2013 | 537 |
| Citable documents | 2014 | 527 |
| Citable documents | 2015 | 487 |
| Citable documents | 2016 | 410 |