windowing query for row of dots to enable cumulative count

windowing example.sql

SELECT		x.[MovementDateTime],
			x.[FirstName],
			x.[LastName],
			x.[Ward_Dept],
			x.[Staging_Post],
			x.[Movement_Type],
			x.[IN_OUT],
			x.[Movement15],
			x.[counter],
			ROW_NUMBER() OVER (PARTITION BY IN_OUT, Movement_Type,Staging_Post,Movement15 ORDER BY (MovementDateTime))AS R_Number
FROM 
		(SELECT [MovementDateTime],
			[FirstName],
			[LastName],
			[Ward_Dept],
			[Staging_Post],
			[Movement_Type],
			[IN_OUT],
			cast(round(floor(cast([MovementDateTime] AS float(53))*24*4)/(24*4),5) AS smalldatetime) AS Movement15,
			(CASE WHEN IN_OUT = 'IN' THEN 1 ELSE -1 END) AS [counter]
				FROM [DB].[dbo].[TABLENAME])x