| D | Notice of Exempt Offering of Securities | March 18, 2019 |  | 
| D | Notice of Exempt Offering of Securities | March 18, 2019 |  | 
| D | Notice of Exempt Offering of Securities | March 18, 2019 |  | 
| RW | Registration Withdrawal Request | March 8, 2019 |  | 
| 8-K | Current report | March 1, 2019 |  | 
| 3 | Initial statement of beneficial ownership of securities | January 22, 2019 |  | 
| 3 | Initial statement of beneficial ownership of securities | January 15, 2019 |  | 
| 3 | Initial statement of beneficial ownership of securities | January 10, 2019 |  | 
| SC 13D | General statement of acquisition of beneficial ownership | January 10, 2019 |  | 
| 3 | Initial statement of beneficial ownership of securities | January 10, 2019 |  |