Quarter	Percent
1960-01-01	3.84
1960-04-01	3.32
1960-07-01	2.60
1960-10-01	1.98
1961-01-01	2.02
1961-04-01	1.73
1961-07-01	1.88
1961-10-01	2.33
1962-01-01	2.85
1962-04-01	2.68
1962-07-01	2.90
1962-10-01	2.93
1963-01-01	2.98
1963-04-01	2.99
1963-07-01	3.48
1963-10-01	3.38
1964-01-01	3.43
1964-04-01	3.50
1964-07-01	3.45
1964-10-01	3.85
1965-01-01	4.04
1965-04-01	4.04
1965-07-01	4.01
1965-10-01	4.32
1966-01-01	4.65
1966-04-01	5.17
1966-07-01	5.40
1966-10-01	5.40
1967-01-01	4.53
1967-04-01	3.98
1967-07-01	3.99
1967-10-01	4.51
1968-01-01	5.05
1968-04-01	6.07
1968-07-01	5.78
1968-10-01	6.02
1969-01-01	6.79
1969-04-01	8.90
1969-07-01	9.15
1969-10-01	8.97
1970-01-01	7.76
1970-04-01	7.60
1970-07-01	6.29
1970-10-01	4.90
1971-01-01	3.71
1971-04-01	4.91
1971-07-01	5.55
1971-10-01	4.14
1972-01-01	3.83
1972-04-01	4.46
1972-07-01	4.87
1972-10-01	5.33
1973-01-01	7.09
1973-04-01	8.49
1973-07-01	10.78
1973-10-01	9.95
1974-01-01	9.35
1974-04-01	11.93
1974-07-01	11.34
1974-10-01	8.53
1975-01-01	5.54
1975-04-01	5.55
1975-07-01	6.24
1975-10-01	5.20
1976-01-01	4.84
1976-04-01	5.48
1976-07-01	5.25
1976-10-01	4.65
1977-01-01	4.69
1977-04-01	5.39
1977-07-01	6.14
1977-10-01	6.56
1978-01-01	6.79
1978-04-01	7.60
1978-07-01	8.45
1978-10-01	10.03
1979-01-01	10.09
1979-04-01	10.29
1979-07-01	11.43
1979-10-01	13.78
1980-01-01	17.19
1980-04-01	9.47
1980-07-01	10.87
1980-10-01	18.90
1981-01-01	14.70
1981-04-01	19.10
1981-07-01	15.87
1981-10-01	12.37
1982-01-01	14.68
1982-04-01	14.15
1982-07-01	10.31
1982-10-01	8.95
1983-01-01	8.77
1983-04-01	8.98
1983-07-01	9.45
1983-10-01	9.47
1984-01-01	9.91
1984-04-01	11.06
1984-07-01	11.30
1984-10-01	8.38
1985-01-01	8.58
1985-04-01	7.53
1985-07-01	7.92
1985-10-01	8.27
1986-01-01	7.48
1986-04-01	6.92
1986-07-01	5.89
1986-10-01	6.91
1987-01-01	6.13
1987-04-01	6.73
1987-07-01	7.22
1987-10-01	6.77
1988-01-01	6.58
1988-04-01	7.51
1988-07-01	8.19
1988-10-01	8.76
1989-01-01	9.85
1989-04-01	9.53
1989-07-01	9.02
1989-10-01	8.45
1990-01-01	8.28
1990-04-01	8.29
1990-07-01	8.20
1990-10-01	7.31
1991-01-01	6.12
1991-04-01	5.90
1991-07-01	5.45
1991-10-01	4.43
1992-01-01	3.98
1992-04-01	3.76
1992-07-01	3.22
1992-10-01	2.92
1993-01-01	3.07
1993-04-01	3.04
1993-07-01	3.09
1993-10-01	2.96
1994-01-01	3.34
1994-04-01	4.25
1994-07-01	4.73
1994-10-01	5.45
1995-01-01	5.98
1995-04-01	6.00
1995-07-01	5.80
1995-10-01	5.60
1996-01-01	5.31
1996-04-01	5.27
1996-07-01	5.30
1996-10-01	5.29
1997-01-01	5.39
1997-04-01	5.56
1997-07-01	5.54
1997-10-01	5.50
1998-01-01	5.49
1998-04-01	5.56
1998-07-01	5.51
1998-10-01	4.68
1999-01-01	4.81
1999-04-01	4.76
1999-07-01	5.22
1999-10-01	5.30
2000-01-01	5.85
2000-04-01	6.53
2000-07-01	6.52
2000-10-01	6.40
2001-01-01	5.31
2001-04-01	3.97
2001-07-01	3.07
2001-10-01	1.82
2002-01-01	1.73
2002-04-01	1.75
2002-07-01	1.75
2002-10-01	1.24
2003-01-01	1.25
2003-04-01	1.22
2003-07-01	1.01
2003-10-01	0.98
2004-01-01	1.00
2004-04-01	1.03
2004-07-01	1.61
2004-10-01	2.16
2005-01-01	2.63
2005-04-01	3.04
2005-07-01	3.62
2005-10-01	4.16
2006-01-01	4.59
2006-04-01	4.99
2006-07-01	5.25
2006-10-01	5.24
2007-01-01	5.26
2007-04-01	5.25
2007-07-01	4.94
2007-10-01	4.24
2008-01-01	2.61
2008-04-01	2.00
2008-07-01	1.81
2008-10-01	0.16
2009-01-01	0.18
2009-04-01	0.21
2009-07-01	0.15
2009-10-01	0.12
2010-01-01	0.16
2010-04-01	0.18
2010-07-01	0.19
2010-10-01	0.18
2011-01-01	0.14
2011-04-01	0.09
2011-07-01	0.08
2011-10-01	0.07
2012-01-01	0.13
2012-04-01	0.16
2012-07-01	0.14
2012-10-01	0.16
2013-01-01	0.14
2013-04-01	0.09
2013-07-01	0.08
2013-10-01	0.09
2014-01-01	0.08
2014-04-01	0.10
2014-07-01	0.09
2014-10-01	0.12
2015-01-01	0.11
2015-04-01	0.13
2015-07-01	0.14
2015-10-01	0.24
2016-01-01	0.36
2016-04-01	0.38
2016-07-01	0.40
2016-10-01	0.54
2017-01-01	0.79
2017-04-01	1.04
2017-07-01	1.15
2017-10-01	1.30
2018-01-01	1.51
2018-04-01	1.82
2018-07-01	1.95