SQL Date Filtering

I have a set of sensors on a production line that are logging data to an SQL 2005 server every second. There are 154 ssensors. To date, there are 306 million records. I’d like to create a view that shows only the data recorded every 15 minutes. I have no control over the sensors. Any thoughts on a view? A simple Select query was added but it takes too long to load (almost 80 million records).

SELECT dbo.FloatData.DateAndTime, dbo.FloatData.Millitm, dbo.FloatData.Val, dbo.FloatData.Status, dbo.FloatData.Marker, dbo.TagData.TagName
FROM dbo.FloatData LEFT OUTER JOIN dbo.TagData ON dbo.FloatData.TagIndex = dbo.TagData.TagIndex
WHERE dbo.FloatData.TagIndex <= 21)