Jaar	Invoer	Uitvoer	Totaal
2009	630.818	655.302	1.286.120
2008	1.008.838	1.117.305	2.126.143
2007	1.030.324	1.178.582	2.208.906
2006	863.039	1.070.871	1.933.910
2005	774.913	959.801	1.734.714
2004	770.151	940.338	1.710.489
2003	689.527	888.091	1.577.618
2002	479.973	895.876	1.375.849
2001	441.296	812.267	1.253.563
2000	364.833	666.284	1.031.117
1999	330.680	581.673	912.353
1998	289.568	480.990	770.558
1997	207.142	396.382	603.524
1996	229.552	382.355	611.907
1995	170.247	378.701	548.948
1994	156.801	325.859	482.660
1993	106.957	253.522	360.479
1992	64.514	161.027	225.541
1991	55.031	137.604	192.635
1990	15.212	194.649	209.861
1989	1.300	199.963	201.263
1988	1.059	149.805	150.864
1987	1.801	95.595	97.396
1986	410	97.154	97.564
1985	380	74.280	74.660
1984	1.322	82.500	83.822
1983	1.754	39.145	40.899
1982	146	12.186	12.332
1981	199	5.864	6.063