Avg start year: 2007 Avg last updated year: 2011
1 1998
1 2000
1 2001
4 2002
4 2004
5 2005
7 2006
7 2007
15 2008
9 2009
13 2010
23 2011
34 2012
83 2013
39 2014
{ 1998 => 1, 2000 => 1, 2001 => 1, 2002 => 4, 2004 => 4, 2005 => 5, 2006 => 7, 2007 => 7, 2008 => 15, 2009 => 9, 2010 => 13, 2011 => 23, 2012 => 34, 2013 => 83, 2014 => 39}
I think that I could do a better job with some of these numbers and I want to go back and fill in some blanks.
3 1996
1 1997
2 1998
1 1999
5 2000
7 2001
3 2002
2 2003
6 2004
6 2005
9 2006
10 2007
13 2008
17 2009
15 2010
20 2011
17 2012
7 2013
{ 1996 => 3, 1997 => 1, 1998 => 2, 1999 => 1, 2000 => 5, 2001 => 7, 2002 => 3, 2003 => 2, 2004 => 6, 2005 => 6, 2006 => 9, 2007 => 10, 2008 => 13, 2009 => 17, 2010 => 15, 2011 => 20, 2012 => 17, 2013 => 7 }
This is bad and I feel bad.
(year.map {|yr,ct| yr * ct }.inject(&:+))/(year.map{|_,c|c}.inject(&:+))