select CONVERT(CHAR(4), wf.Createdate, 100) + CONVERT(CHAR(4), wf.Createdate, 120) AS MonthYear,
(select COUNT(CONVERT(CHAR(4), Createdate, 100) + CONVERT(CHAR(4),Createdate, 120)) from mstr_workforce where Createdate<=wf.Createdate) as RuninngTotal
from mstr_workforce as wf where DATEADD(D, 0, DATEDIFF(D, 0,wf.Createdate)) Between
'01/01/2015' and '06/15/2015' group by wf.Createdate