| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | 26 Jul 2021 | 23 Jul 2021 | 000-55639 | |
| 4 | Open Document | Open Filing | 15 Apr 2020 | 14 Apr 2020 | 000-55639 | |
| 4 | Open Document | Open Filing | 27 Mar 2019 | 11 Jan 2019 | 000-55639 | |
| 3 | Open Document | Open Filing | OWNERSHIP DOCUMENT | 21 Mar 2018 | 13 Feb 2018 | 000-55639 |