Extracting designated contracting states from TLS221 (inpadoc legal data)

Several informations are contained in TLS221_inpadoc_prs; those about designated contracting states (prs code AK) and extensions (PRS code AX) are among the most relevant, even if they are somehow tricky to extract (all patent authorities alltogether in one text field).

Even if the work is done, we can also notice that data coverage differs much from application authority to application authority.

Here below you can find a application year wise list of pubblications for EPO and USPTO, and the percentage of those containing data type AK and AX...

	USPTO			EPO
Appl year	# publ	# DCST	% DCST	# publ	# dcst	% dcst
1980	66941	887	1,3%	19724	19723	100,0%
1981	64310	12496	19,4%	24959	24956	100,0%
1982	65461	342	0,5%	28522	28522	100,0%
1983	61996	274	0,4%	31609	31608	100,0%
1984	67511	343	0,5%	36952	36951	100,0%
1985	71984	408	0,6%	39375	39373	100,0%
1986	75735	484	0,6%	43084	43081	100,0%
1987	82167	5218	6,4%	45817	45815	100,0%
1988	90751	13731	15,1%	52186	52183	100,0%
1989	96896	564	0,6%	57727	57724	100,0%
1990	100085	517	0,5%	63907	63902	100,0%
1991	100999	497	0,5%	59280	59269	100,0%
1992	104609	510	0,5%	60630	60618	100,0%
1993	109040	5422	5,0%	60075	60064	100,0%
1994	124162	15101	12,2%	62015	62006	100,0%
1995	145504	572	0,4%	65329	65320	100,0%
1996	146014	616	0,4%	71459	71421	99,9%
1997	171083	937	0,5%	80568	80513	99,9%
1998	171172	7901	4,6%	91120	91054	99,9%
1999	186262	19353	10,4%	98897	98823	99,9%
2000	212820	14529	6,8%	109722	109272	99,6%
2001	276700	17148	6,2%	115533	115310	99,8%
2002	285002	43168	15,1%	113433	113361	99,9%
2003	300232	21017	7,0%	116409	116315	99,9%
2004	341187	21107	6,2%	121714	121542	99,9%
2005	368017	45444	12,3%	127760	127619	99,9%
2006	333817	22775	6,8%	130949	130822	99,9%
2007	301763	20865	6,9%	128247	128222	100,0%
2008	180053	25704	14,3%	103889	103883	100,0%
2009	13263	299	2,3%	29261	29261	100,0%

(bytheway another good question would be: why in EPO tables giving possible PRS by application authority do not exist even AK and AX for USPTO but we have it in the files?)