year	all	orig	imputed
1996	2.4851	2.4042	3.1759
1997	2.4293	2.2866	3.7124
1998	2.3964	2.2757	3.6625
1999	2.8051	2.307	6.9998
2000	3.1193	2.3473	10.4005
2001	2.8164	2.0472	9.4432
2002	2.7931	2.0651	9.0335
2003	2.6995	1.9547	8.8618
2004	2.5816	1.8298	8.4879
2005	2.5912	1.9277	7.3519
2006	1.9599	1.8718	2.666
2007	1.661	1.648	1.7617
2008	1.6034	1.573	1.8722
2009	1.5681	1.5602	1.6362
2010	1.4416	1.3848	1.8679