Friday is the final day for households to mail back their 2010 Census forms, if people want to reduce their chances of having a census taker knock at their door. After today, the Census Bureau will begin planning the expensive personal door-to-door visits to non-responding households that begin as early as April 29.

The Census Bureau saves about $85 million in operational costs for every one percent of households that mail back their forms. If every household completed and mailed back their census form, taxpayers could reduce the cost of taking the census and save $1.5 billion. In 2000, the nation reversed a three-decade decline in mail response rates and saved $305 million.

As of Friday morning, 68 percent of households nationwide have mailed back their census forms. Washington state edged above the national rate with 69 percent on Tuesday – and has remained at that rate. King, Snohomish, Yakima and Clark counties have 69 percent as well.

Counties with the highest participation rates were Jefferson (76 percent), Clallum (75 percent) and Island (73 percent). Asotin and Skagit counties were at 72 percent. Benton, Walla Walla and Thurston counties were at 71 percent. Lagging behind were Ferry (50 percent ), Okanogan (49percent ) and Pend Oreille (48 percent ) counties. Mail back participation rates are updated daily after 1 p.m. (PST) at www.2010census.gov.

For the first time, the Census Bureau has mailed replacement forms to areas with historically lower mail response rates. Research shows that the replacement forms will help increase mail response in those areas, which significantly reduces the cost of taking the census.

All census responses are confidential. Answers are protected by law and cannot be shared with anyone. Extreme measures are taken to protect the identity of individuals and businesses. By law, the Census Bureau cannot share respondents’ individually identifiable answers with anyone, including tribal housing authorities, other federal agencies and law enforcement entities.

If you did not receive a Census form or have misplaced it, visit: http://2010.census.gov/2010census/take10map/ to find a “Be Counted” or questionnaire assistance center site in your neighborhood, where forms are available.