How can I select data from this table
Yr     Month    El1       Value    
----   ------   -------   ------
2017   2        AT010     100        
2017   3        AT010     100         
2017   4        AT010     50        
2017   5        AT010     150     
2017   3        BE020     10      
.......
and insert it into another table in the following way
Yr     Month    El1       Value    
----   ------   -------   ------
2017   0        AT010     0        
2017   1        AT010     0         
2017   2        AT010     100        
2017   3        AT010     200  
2017   4        AT010     250         
2017   5        AT010     400        
2017   6        AT010     400        
2017   7        AT010     400        
2017   8        AT010     400    
2017   9        AT010     400  
2017   10        AT010     400    
2017   11        AT010     400        
2017   12        AT010     400    
2017   0        BE020     0  
2017   1        BE020     0    
2017   2        BE020     0  
2017   3        BE020     10   
2017   4        BE020     10   
2017   5        BE020     10   
2017   6        BE020     10   
2017   7        BE020     10   
2017   8        BE020     10    
2017   9        BE020     10   
2017   10        BE020    10   
2017   11        BE020    10    
2017   12        BE020    10 
.......
I am trying to insert missing months from 0 to 12 and calculate running total at the same time. I used this suggestion for running total calculation; however, I can't figure out how to enter missing month. This code will be used in the stored procedure for a daily ETL job.