Quarter	Number of Buildings, Seasonally Adjusted
2001-01-01	8253.64269320000
2001-04-01	7696.59174466667
2001-07-01	7071.85263226667
2001-10-01	15354.62811766670
2002-01-01	8607.55852533334
2002-04-01	4809.99356133333
2002-07-01	5673.89216966667
2002-10-01	6504.27743666667
2003-01-01	6259.14514743333
2003-04-01	6620.04823633333
2003-07-01	7095.18546300000
2003-10-01	7869.78119533333
2004-01-01	9073.54201950000
2004-04-01	8473.31033700000
2004-07-01	8766.93938466666
2004-10-01	7351.59006006667
2005-01-01	8897.61306033333
2005-04-01	8349.40740566666
2005-07-01	9008.63289300000
2005-10-01	9166.02322113333
2006-01-01	8756.26133620000
2006-04-01	11777.07780366670
2006-07-01	11627.97364500000
2006-10-01	13962.46762193330
2007-01-01	14027.04771350000
2007-04-01	14999.00733333330
2007-07-01	16128.72334833330
2007-10-01	16586.23647633330
2008-01-01	16728.62479400000
2008-04-01	15091.48554833330
2008-07-01	14277.85152266670
2008-10-01	12202.03758266670
2009-01-01	11188.65565666670
2009-04-01	11437.55854000000
2009-07-01	11868.48118033330
2009-10-01	13209.09633816670
2010-01-01	12540.77353866670
2010-04-01	14287.13149766670
2010-07-01	13551.35839366670
2010-10-01	12328.49548640000
2011-01-01	12979.28545733330
2011-04-01	13374.49747166670
2011-07-01	14262.04447566670
2011-10-01	13582.18200001570
2012-01-01	13247.01382366670
2012-04-01	13319.33136733330
2012-07-01	10445.74416100000
2012-10-01	10361.90402643330
2013-01-01	10108.82206500000
2013-04-01	9208.71965733333
2013-07-01	11359.48021200000
2013-10-01	11738.70035160000
2014-01-01	12895.74502666670
2014-04-01	10783.18192733330
2014-07-01	12619.75447066670
2014-10-01	13014.87143106670
2015-01-01	13267.36227166670
2015-04-01	13016.48981500000
2015-07-01	14557.63733500000
2015-10-01	15280.09428370000
2016-01-01	14318.50775333330
2016-04-01	13836.78242333330
2016-07-01	14344.69971370000
2016-10-01	11948.21807120000
2017-01-01	16811.93937233330
2017-04-01	17621.37960166670
2017-07-01	17252.71021856670
2017-10-01	17087.65104825000
2018-01-01	18761.65192633330
2018-04-01	18128.77627166670
2018-07-01	19138.17744336670