year	stat	im_
1987	"mean"	35.89
1987	"N"	87
1988	"mean"	30.49
1988	"N"	88
1989	"mean"	28.2
1989	"N"	87
1990	"mean"	24.35
1990	"N"	96
1991	"mean"	26.85
1991	"N"	80
1992	"mean"	26.2
1992	"N"	76
1993	"mean"	25.34
1993	"N"	79
1994	"mean"	22.07
1994	"N"	79
1995	"mean"	21.83
1995	"N"	78
1996	"mean"	22.35
1996	"N"	58
1997	"mean"	19.55
1997	"N"	59
1998	"mean"	18.74
1998	"N"	58
1999	"mean"	18.1
1999	"N"	55
2000	"mean"	18.31
2000	"N"	51
2001	"mean"	17.77
2001	"N"	63
2002	"mean"	15.73
2002	"N"	61
2003	"mean"	17.6
2003	"N"	62
2004	"mean"	14.56
2004	"N"	30
