| 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 | 18 May 2020 | 15 May 2020 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 16 May 2019 | 15 May 2019 | 000-26946 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | 17 Aug 2018 | 15 Aug 2018 | 000-26946 |
| 3 | Open Document | Open Filing | PRIMARY DOCUMENT | 16 Aug 2018 | 15 Aug 2018 | 000-26946 |