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 | 3 |
| Non-citable documents | 2001 | 7 |
| Non-citable documents | 2002 | 12 |
| Non-citable documents | 2003 | 12 |
| Non-citable documents | 2004 | 8 |
| Non-citable documents | 2005 | 5 |
| Non-citable documents | 2006 | 5 |
| Non-citable documents | 2007 | 9 |
| Non-citable documents | 2008 | 12 |
| Non-citable documents | 2009 | 14 |
| Non-citable documents | 2010 | 41 |
| Non-citable documents | 2011 | 40 |
| Non-citable documents | 2012 | 38 |
| Non-citable documents | 2013 | 8 |
| Non-citable documents | 2014 | 5 |
| Non-citable documents | 2015 | 4 |
| Non-citable documents | 2016 | 3 |
| Non-citable documents | 2017 | 4 |
| Non-citable documents | 2018 | 4 |
| Non-citable documents | 2019 | 9 |
| Non-citable documents | 2020 | 8 |
| Non-citable documents | 2021 | 7 |
| Non-citable documents | 2022 | 4 |
| Citable documents | 1999 | 10 |
| Citable documents | 2000 | 17 |
| Citable documents | 2001 | 30 |
| Citable documents | 2002 | 66 |
| Citable documents | 2003 | 75 |
| Citable documents | 2004 | 92 |
| Citable documents | 2005 | 74 |
| Citable documents | 2006 | 85 |
| Citable documents | 2007 | 93 |
| Citable documents | 2008 | 96 |
| Citable documents | 2009 | 80 |
| Citable documents | 2010 | 62 |
| Citable documents | 2011 | 67 |
| Citable documents | 2012 | 73 |
| Citable documents | 2013 | 79 |
| Citable documents | 2014 | 82 |
| Citable documents | 2015 | 78 |
| Citable documents | 2016 | 72 |
| Citable documents | 2017 | 76 |
| Citable documents | 2018 | 78 |
| Citable documents | 2019 | 84 |
| Citable documents | 2020 | 71 |
| Citable documents | 2021 | 76 |
| Citable documents | 2022 | 73 |