| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | FORM 4 | 13 May 2021 | 11 May 2021 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | 13 May 2020 | 12 May 2020 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | 16 May 2019 | 14 May 2019 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | 16 May 2018 | 15 May 2018 | 000-18953 |
| 3 | Open Document | Open Filing | FORM 3 | 19 May 2017 | 16 May 2017 | 000-18953 |