Taxpayer a college professor age 58 purchased and moved into a house on August 1, 2012. He used the house continuously until 9/1/2013 on which date he went abroad for a one year sabbatical leave. During part of the period of leave, te property was unoccupied and it was leased during the remainder of the period. On October 1, 2014 one month after returning from such leave he sold the house. Can taxpayer use the exclusion for the sale of residence?