Quarter	Percent
1975-01-01	5386
1975-04-01	6953
1975-07-01	5552
1975-10-01	5137
1976-01-01	5800
1976-04-01	6202
1976-07-01	5819
1976-10-01	6795
1977-01-01	9588
1977-04-01	6348
1977-07-01	7275
1977-10-01	6191
1978-01-01	6133
1978-04-01	8252
1978-07-01	7778
1978-10-01	6245
1979-01-01	7983
1979-04-01	8301
1979-07-01	9267
1979-10-01	7923
1980-01-01	7286
1980-04-01	7684
1980-07-01	8824
1980-10-01	7104
1981-01-01	6379
1981-04-01	8639
1981-07-01	12849
1981-10-01	6174
1982-01-01	8681
1982-04-01	7789
1982-07-01	7567
1982-10-01	7604
1983-01-01	6919
1983-04-01	8994
1983-07-01	9942
1983-10-01	5372
1984-01-01	5190
1984-04-01	4771
1984-07-01	5341
1984-10-01	4983
1985-01-01	4476
1985-04-01	5011
1985-07-01	4465
1985-10-01	4051
1986-01-01	3199
1986-04-01	3211
1986-07-01	3331
1986-10-01	3206
1987-01-01	2962
1987-04-01	3101
1987-07-01	3715
1987-10-01	2452
1988-01-01	2632
1988-04-01	2718
1988-07-01	3296
1988-10-01	3219
1989-01-01	4101
1989-04-01	4799
1989-07-01	5210
1989-10-01	4913
1990-01-01	5234
1990-04-01	4677
1990-07-01	5573
1990-10-01	4320
1991-01-01	4419
1991-04-01	3626
1991-07-01	4922
1991-10-01	5179
1992-01-01	3704
1992-04-01	4500
1992-07-01	4561
1992-10-01	4932
1993-01-01	4931
1993-04-01	5198
1993-07-01	4415
1993-10-01	4313
1994-01-01	4811
1994-04-01	4464
1994-07-01	5858
1994-10-01	4827
1995-01-01	6679
1995-04-01	5647
1995-07-01	6396
1995-10-01	4350
1996-01-01	7610
1996-04-01	6640
1996-07-01	8294
1996-10-01	6966
1997-01-01	6962
1997-04-01	8821
1997-07-01	6975
1997-10-01	7004
1998-01-01	9280
1998-04-01	9170
1998-07-01	12232
1998-10-01	9276
1999-01-01	14370
1999-04-01	14303
1999-07-01	17231
1999-10-01	17891
2000-01-01	17163
2000-04-01	18985
2000-07-01	19574
2000-10-01	18106
2001-01-01	16492
2001-04-01	16104
2001-07-01	14515
2001-10-01	13618
2002-01-01	12105
2002-04-01	15236
2002-07-01	13501
2002-10-01	10213
2003-01-01	9511
2003-04-01	13118
2003-07-01	14394
2003-10-01	12582
2004-01-01	17054
2004-04-01	18653
2004-07-01	17097
2004-10-01	16772
2005-01-01	18913
2005-04-01	21938
2005-07-01	18190
2005-10-01	16609
2006-01-01	16454
2006-04-01	15014
2006-07-01	15486
2006-10-01	13054
2007-01-01	15654
2007-04-01	18201
2007-07-01	15838
2007-10-01	13135
2008-01-01	13301
2008-04-01	12598
2008-07-01	11532
2008-10-01	10375
2009-01-01	10256
2009-04-01	7739
2009-07-01	5362
2009-10-01	3457
2010-01-01	3585
2010-04-01	3043
2010-07-01	2817
2010-10-01	2159
2011-01-01	3075
2011-04-01	2599
2011-07-01	1887
2011-10-01	1537
2012-01-01	1263
2012-04-01	1166
2012-07-01	1540
2012-10-01	1420
2013-01-01	1860
2013-04-01	1496
2013-07-01	1252
2013-10-01	1394
2014-01-01	1446
2014-04-01	1492
2014-07-01	1783
2014-10-01	1905
2015-01-01	2514
2015-04-01	2637
2015-07-01	2345
2015-10-01	2754
2016-01-01	2534
2016-04-01	2340
2016-07-01	4362
2016-10-01	3245
2017-01-01	3754
2017-04-01	3630
2017-07-01	3764
2017-10-01	4292
2018-01-01	5917
2018-04-01	4951