running total wih constant numbers TSQL : I have data looks like this

    '
    MILEAGE	January	February	........December
	0	`       0   	0	
    2	    	0.066	0.052
    3		    0.081   0
    5			0		0.062
    6		    0.080	0	.........
    813	        0	    0  and so on

'
I want the data to look like this

    Mileage      January   February ..... December
      0         (Total of Mileage less and equal to zero for each month)
      2000       Total of Mileage upto 2000 for each month
      4000       Total of Mileage upto 4000 for each month
      6000       Total of Mileage upto 6000 for each month 
      8000       and so on....
      10000
      12000
      14000
      2 thousand increment up till 
      50000
'

Thank you very much for your help.I am using sql 2008 R2 and not sure how to achieve this  
