| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 21 May 2021 | 20 May 2021 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 17 May 2021 | 15 May 2021 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 18 May 2020 | 15 May 2020 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 21 Feb 2020 | 19 Feb 2020 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 17 May 2019 | 15 May 2019 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 21 May 2018 | 17 May 2018 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 17 May 2018 | 15 May 2018 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 20 Feb 2018 | 15 Feb 2018 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 19 May 2017 | 18 May 2017 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 16 May 2017 | 15 May 2017 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 13 Apr 2017 | 11 Apr 2017 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 16 Feb 2017 | 14 Feb 2017 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 09 Feb 2017 | 07 Feb 2017 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 05 Jan 2017 | 03 Jan 2017 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 23 May 2016 | 19 May 2016 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 17 May 2016 | 15 May 2016 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 17 Feb 2016 | 15 Feb 2016 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 10 Feb 2016 | 02 Feb 2016 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 26 May 2015 | 21 May 2015 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 19 Feb 2015 | 15 Feb 2015 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 21 Jan 2014 | 16 Jan 2014 | 000-26946 |
| 3 | Open Document | Open Filing | PRIMARY DOCUMENT | 15 Jan 2014 | 06 Jan 2014 | 000-26946 |