You are not eligible to purchase a private property at the moment.
Let me explain.
Your effective date of resale is from May 2010 thus only 3 years of MOP is applicable for your case but....
Minimum Occupation Period (MOP) means:
HDB flat owners must have physically occupied their flats for a period of time, referred to as Minimum Occupation Period (MOP), before they are eligible to sell it in the open market.
As you mentioned that you have not physically occupied your unit since Dec 2010, thus only 6 to 7 months has only being counted into your MOP.
Feel free to contact me if you have any property needs.
M: (+65) 9111 5171