| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | Jul 26, 2021 | Jul 23, 2021 | 000-55639 | |
| 4 | Open Document | Open Filing | Apr 15, 2020 | Apr 14, 2020 | 000-55639 | |
| 4/A | Open Document | Open Filing | Dec 3, 2019 | Nov 27, 2019 | 000-55639 | |
| 4 | Open Document | Open Filing | Dec 2, 2019 | Nov 27, 2019 | 000-55639 | |
| 4 | Open Document | Open Filing | Jul 23, 2019 | Jul 22, 2019 | 000-55639 | |
| 4 | Open Document | Open Filing | Jul 18, 2019 | Jul 17, 2019 | 000-55639 | |
| 3 | Open Document | Open Filing | Feb 27, 2019 | Jun 27, 2017 | 000-55639 |