| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Jun 10, 2021 | Jun 8, 2021 | 001-13991 |
| 4 | Open Document | Open Filing | 4 | Jul 10, 2020 | Jul 9, 2020 | 001-13991 |
| 4 | Open Document | Open Filing | 4 | May 28, 2019 | May 23, 2019 | 001-13991 |
| 4 | Open Document | Open Filing | 4 | Jun 14, 2018 | Jun 13, 2018 | 001-13991 |
| 4 | Open Document | Open Filing | 4 | May 29, 2018 | May 24, 2018 | 001-13991 |
| 4 | Open Document | Open Filing | 4 | May 30, 2017 | May 25, 2017 | 001-13991 |
| 4 | Open Document | Open Filing | 4 | May 31, 2016 | May 26, 2016 | 001-13991 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 27, 2015 | May 22, 2015 | 001-13991 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | Aug 7, 2014 | Aug 6, 2014 | 001-13991 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 23, 2014 | May 22, 2014 | 001-13991 |