| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4/A | Open Document | Open Filing | OWNERSHIP DOCUMENT | Nov 24, 2021 | Nov 22, 2021 | 000-55768 |
| 4 | Open Document | Open Filing | Nov 16, 2021 | Nov 12, 2021 | 000-55768 | |
| 4 | Open Document | Open Filing | May 4, 2021 | Apr 30, 2021 | 000-55768 | |
| 4 | Open Document | Open Filing | Mar 3, 2021 | Mar 2, 2021 | 000-55768 | |
| 4 | Open Document | Open Filing | Mar 3, 2020 | Jan 3, 2020 | 000-55768 | |
| 3 | Open Document | Open Filing | Mar 3, 2020 | Nov 26, 2019 | 000-55768 |