| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | May 23, 2022 | May 19, 2022 | 000-55610 | |
| 4 | Open Document | Open Filing | May 6, 2021 | May 4, 2021 | 000-55610 | |
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Feb 17, 2021 | Feb 16, 2021 | 000-55610 |
| 4 | Open Document | Open Filing | Jan 7, 2021 | Jan 5, 2021 | 000-55610 | |
| 4 | Open Document | Open Filing | Nov 12, 2020 | Nov 10, 2020 | 000-55610 | |
| 4 | Open Document | Open Filing | Jul 15, 2020 | Jul 14, 2020 | 000-55610 | |
| 4 | Open Document | Open Filing | Jun 3, 2020 | Jun 1, 2020 | 000-55610 | |
| 3 | Open Document | Open Filing | FORM 3 | May 31, 2019 | Jan 1, 2012 | 000-55610 |