Created with Raphaël 2.1.2
19
2
4
6
8
10
12
14
16
18
0
1971
0
1972
0
1973
0
1974
0
1975
0
1976
0
1977
0
1978
0
1979
0
1980
0
1981
0
1982
0
1983
0
1984
0
1985
0
1986
0
1987
0
1988
0
1989
0
1990
0
1991
0
1992
0
1993
0
1994
0
1995
0
1996
0
1997
0
1998
0
1999
0
2000
0
2001
0
2003
0
2004
0
2005
0
2006
8
2007
11
2008
15
2009
16
2010
13
2011
8
2012
16
2013
9
2014
13
2015
12
2016
19
2017