e the law. And we do protect these individual responses, put out basically just tables, just tabulations, and not even the Patriot Act can override these protections.
We do share the data with the National Archives and they keep them confidential as well. They have to be sworn Census agents, the people who see these data, and they can release them to the public after 72 years. And that is a big basis for a lot of genealogical research in the United States, tracing family trees and that sort of thing. So we do take that very seriously.
This is really the largest peacetime activity, domestic activity, the federal government undertakes, and it’s really not just now. It takes roughly 14 years from the time we start planning until the time we finish releasing the data. So for example, I’ve already starting working on our 2020 census. As a matter of fact, I started in 2008 working on our 2020 census, and we’re well along in planning that census.
The idea of the census is to count every person living in the United States on April 1, 2010, citizens and non-citizens. We estimate there will be about 309 million people counted in roughly 134 million housing units. It covers all 50 states, the District of Columbia. It covers Puerto Rico. It also covers the U.S. territories, which are the island areas of the Virgin Islands, the Northern Mariana Islands, American Samoa and Guam. They all have their censuses as well that we do at this time.
The key changes in the 2010 Census from before – we have what we’re calling a short form-only census this time. There are only 10 questions for the first person, seven questions for everybody else. We estimate the average household will take only about 10 minutes to fill out the questionnaire. It’s really the shortest census form since 1790, which I think had seven questions.
We used handheld computers equipped with GPS, global positioning system, for a nationwide address canvassing. About a year ago, in April through July of 2009, we sent about 140,000 people out to walk or drive every street in the U.S. to get a GPS coordinate for every housing unit, and we had already spent a good deal of money realigning all of our streets to GPS network. So the idea of this undertaking was to minimize what we call “geocoding” errors, to make sure the housing unit was in the right place, the right block, so that when people draw their lines there for redistricting, we have the people in the right place.
We also do a census in group quarters, not just housing units. Group quarters are places like prisons, hospitals, nursing homes, college dormitories, places where people live together but may not have a separate, like, kitchen. We have made a special effort this decade to identify the group quarters, and are about to start counting people in those group quarters.
We are mailing, for the first time, a bilingual questionnaire in – about 13 million households will get an English and Spanish questionnaire. We think that will improve response rates in the heavily Hispanic neighborhoods.
One other change we are making is for the first time we’re using a replacement questionnaire. I’ll go through the timing in a little bit, but we have found through research that sending replacement questionnaires to the people who haven’t responded, substantially increases the mail response, which then reduces the cost – overall cost of the census.
So we expect to – we’ve mailed questionnaires already. This was March 15th
to the 17th
. You should have gotten one. In our mail – what we call our mail out areas, about 20 million housing units got – households, got these questionnaires. We actually have to other operations. We have one operation in rural areas without good mailing addresses. In most of those areas, we will take a questionnaire and hang it on people’s doorknobs and ask them to mail it back, because we can’t mail to post office boxes and – or rural routes, but they can get mail picked up there. So we’ll hang it on their doorknobs, they’ll fill it out, put in their mailbox to be picked up and it will come back to us.
And ther