How long does 1-824 takes to be approved.I applied for I-824 (April 2013)for my spouse who is outside the country

I applied for I-824 (April 2013)for my spouse who is outside the country while my my I-485(employment EB3 July 2007) was still pending. I-485 approved and green card received in June 2013. I-824 still pending. USCIS confirmed that they linked both petition before 1-485 was approved I thought it was suppose to be approved together. How long am I expected to wait for approval. Filed 1-824 at Texas(office that processed I-485) but it was sent to Vermont office. Also how soon will USCIS notify NVS