Conversation so far:
How were Drake's early mix tapes distributed?
Drake self-released his debut mixtape
How many copies of Drake self-released his debut mixtape sold?
Drake's mixtape was released for sale only, and confirmed to have sold over 6,000 copies

Question: When did he create his next mix tape?
Self-contained rewrite: When did Drake create his next mix tape after his self-released debut mixtape?