As a result of our continuous effort to improve the quality of the estimates the 2006 weighting methodology was modified in order to ensure total consistency between the estimates of householders, households, and occupied housing units. This has not been the case prior to 2006. With this data release, the estimates of occupied housing units, households, and householders will all be equal. In addition, the modification also reduces the differences between estimates of spouses and married-couple households and between the estimates of unmarried partners and unmarried-partner households. See the Changes to the Estimation for detailed information regarding which tables are most affected and the impact on the estimates had this methodology been applied in 2005.