id: 36 yr ( 3, (3, 0, 0, 0)) (( 2.7, 2.3 ), ( 26.4, 6.1 ))
 +29          +9 
+    +    + 
|     2009     
|        2010  
|          
|           
+    +    + 
|           
|  2011        
|           
|           
+    +    + 
|           
|           
|           
|           
+    +    + 
|           
|           
|           
|           
+    +    + 
|           
|           
|           
|           
+    +    + 
|           
|           
|           
|           
 0----+----+