Although moderators are not privy to the algorithm behind this determination, it's unlikely to be reputation related. More likely by far is that of the 12 questions you've asked, only 3 remain open and not deleted.
Stack Exchange management have provided a more detailed breakdown of contributing factors, including this part:
Basically, the system trains on how we'll you've done overall (either your entire account history, or the last 45 days for newer accounts, dropping the most negatively scored), and how well you've done recently (the last 15 days). That gets us the following:
- Number of questions asked in the last 45 days
- Average score of your questions in that time
- Number of questions asked in the last 15 days
- Average score of your questions in that time
- Average time elapsed between questions in the last 45 and 15 days
The only ways to improve this situation are to found in these instructions.