| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | FORM 4 | Dec 14, 2021 | Dec 13, 2021 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | Dec 3, 2021 | Dec 3, 2021 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | Nov 24, 2021 | Nov 23, 2021 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | Sep 14, 2021 | Sep 13, 2021 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 13, 2021 | May 11, 2021 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | Mar 11, 2021 | Mar 10, 2021 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | Nov 12, 2020 | Nov 10, 2020 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | Aug 12, 2020 | Aug 11, 2020 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 13, 2020 | May 12, 2020 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 16, 2019 | May 14, 2019 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 16, 2018 | May 15, 2018 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 16, 2017 | May 16, 2017 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 24, 2016 | May 24, 2016 | 000-18953 |
| 4/A | Open Document | Open Filing | FORM 4/A | Mar 3, 2016 | May 19, 2015 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 20, 2015 | May 19, 2015 | 000-18953 |
| 4 | Open Document | Open Filing | FORM 4 | May 21, 2014 | May 20, 2014 | 000-18953 |