| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 11, 2021 | May 7, 2021 | 001-32924 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 12, 2020 | May 8, 2020 | 001-32924 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 14, 2019 | May 10, 2019 | 001-32924 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 15, 2018 | May 11, 2018 | 001-32924 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 15, 2017 | May 11, 2017 | 001-32924 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 17, 2016 | May 13, 2016 | 001-32924 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | May 22, 2015 | May 14, 2015 | 001-32924 |
| 3 | Open Document | Open Filing | PRIMARY DOCUMENT | May 22, 2015 | May 12, 2015 | 001-32924 |