id: 21 yr ( 7, (7, 0, 0, 0)) (( 1.2, 1.4 ), ( 6.2, 4.5 ))
 +9                        +8 
|                         
|                      2017  
+    +    +    +    +    +
|                         
|               2014         
|                         
|                         
+    +    +   +    +    +
|            2012 11  2015         
|                         
|                         
|         2016               
+    +    +    +    +    +
|                         
|     2013                   
|                         
|                         
+    +    +    +    +    +
|                         
|                         
|                         
|                         
+    +    +    +    +    +
|                         
|                         
|                         
|                         
 0----+----+----+----+----