Hundreds of thousands of families have taken these credits, but the states do not track whether families in public or private schools used them. [46] See, for example: <a href="http://www.allianceforschoolchoice.org/_files/2006/2005_SchoolChoiceYearbook.pdf,">http://www.allianceforschoolchoice.org/_files/2006/2005_SchoolChoiceYearbook.pdf,</a> http://www.friedmanfoundation.org/news/2006-06-21.html, and http://www.friedmanfoundation.org/news/2006-06-02.html.