"mass"	"year"
2.259	2004
2.247	2004
2.254	1987
2.298	1988
2.287	1971
2.254	2007
2.268	2007
2.214	1974
2.268	2007
2.274	2004
2.271	1997
2.268	1994
2.298	1974
2.292	1996
2.274	1999
2.234	1993
2.238	1998
2.252	2000
2.249	2007
2.234	2001
2.275	1994
2.23	1972
2.236	1992
2.233	1970
2.255	2001
2.277	2001
2.256	2004
2.282	2001
2.235	2001
2.235	2002