id: 20 yr ( 8, (5, 0, 0, 3)) (( 2.5, 2.6 ), ( 3.0, 1.5 ))
 +7        |                    +6 
         |                     
         |                  2016  
    +    +    +    +    +    + 
         |                     
         |                     
         |                  2015  
         |                     
    +    +    +    +    +    + 
         |              2017      
         |                     
         |                     
         |                     
    +    +    +    +    +    + 
         |                     
         |                     
         |                     
         |     2011              
    +    +    +    +    +    + 
         |                     
         |                     
         2012                     
         |                     
    +    +    +    +    +    + 
         2018                     
         |                     
         |                     
         |                     
--2014 13-+----+----+----+----+----+-
         |                     
         |                    -2