From 2002–11, there has been negative net migration, with an annual negative 109 net immigrants from 2006–11. In 2009 there were 1,820 arrivals and 1,736 departures, for a positive rate of 84 immigrants. This was the first time since collecting data in 2002, there was a positive rate. Data on arrivals and departures collected by the Nauruan Customs and Immigration Office is not available, so specific immigration data is unavailable. As of the 2011 census, 57% of the population over 15 years old were legally or de facto married, 35% were never married, while 7% were either widowed, separated, or divorced. There are 1,647 households in Nauru, making an average household size of 6.0 persons per household.. How much of the population over 15 years old were never married as of 2011?