id: 28 yr ( 8, (8, 0, 0, 0)) (( 2.8, 3.2 ), ( 13.1, 6.8 ))
 +19                     +13 
+    +    +    +    +  
|                   2011  
|                      
|                      
|                      
+    +    +    +    +  
|              2017       
|                      
|                      
|           2018          
+    +   2014 12    +    +  
|                      
|        2015             
|                      
|                      
+    +2016   +    +    +  
|    2013                 
|                      
|                      
|                      
+    +    +    +    +  
|                      
|                      
|                      
|                      
+    +    +    +    +  
|                      
|                      
|                      
|                      
 0----+----+----+----+-