Select sum of CreationUtcTime , Avg time and count between speed change from 0 in sql query

Here in the data below, I want to get the CreationUTC time sum by calculating time difference when the data is changing and sum all the time differences whenever the speed data changes from 0 and will take that change as an event from idle to running state. I want to calculate sum of all the idle time, average of idle time and count of idle time for this set of data.

Ex: - Like data is changing in 4th row from 0 to 85 I need first set of time difference from row 1st and 5th second from 5th to 11th and last set will be 3. So count becomes 3 avg will be sum of the time differences by 3.

I want this to be performed as sql query and will later i will convert this into .net linq query in my .net code.

Please ignore formatting as I am very novice in stack overflow.

SELECT CreationUtcTime, Speed, convert(varchar,(CreationUtcTime - LAG(CreationUtcTime) OVER (ORDER BY CreationUtcTime)),108) AS diff     
FROM assetstatusrecords
WHERE Speed <> 0.00
ORDER BY CreationUtcTime

will give the sum of the time and then you can proceed with count and average of the data easily.