id: 306 yr ( 11, (7, 0, 3, 1)) (( 3.8, 3.7 ), ( 3.0, 2.1 ))
 +13     |                        +12 
      |                         
 +    +    +    +    +    +  2011 +
      |                         
      |                         
      |                         
      |                         
 +    +    +    +    +    +    +
      |                         
      |                         
      |                         
      |                         
 +    +    +    +    +    +    +
      |                         
      |                         
      |         2016               
      |                         
 +    +    +  2018 +    +    +    +
      |                         
      |     2017                   
      |                         
      | 2013                      
 +    +    +    +    +    +    +
      2015 12   2020                     
      |                         
      |                         
      |                         
-+2014---+----+----+----+----+----+
      |                         
  2019   |                         
      |                         
    2021 |                         
 +    +    +    +    +    +    +
 -2     |                        -2