Reference previous row to get value

[vrocca]

Hi all,

I have a dataset with Vehicles, Dates, and Odometer. I'm trying to create a calculation that returns the prior odometer reading for each row. I have followed several examples on the web and they work for the most part, but my issue is that I have some bad data where the odometer readings are incorrect and therefore not incremental (i.e. for 4/1/17 it may read 23,500  and then for 4/5/17 it may read 22,500). 

The formula I've been working on looks like this:

Previous Odometer := CALCULATE(MAX(Transactions[Odometer #]),ALL(Transactions),Transactions[Vehicle #] = EARLIER(Transactions[Vehicle #]),Transactions[Transaction Date] < EARLIER(Transactions[Transaction Date])  )

What happens in the scenario where the odometer has a bad reading is that it keeps using that value for all future readings, and throws off the calculations from that point forward.

Example:

Transaction Date          Odometer#          Previous Odometer

02/08/17                      66770                   66320

02/15/17                      97315 (bad data)  66770                              

02/20/17                      67630                   97315

02/27/17                      68056                   97315   <-- here is my issue. this should read 67630. Value keeps repeating for all rows below after this

03/04/17                      68483                   97315

Any suggestions on how I need to modify my DAX formula so that I don't get the same value being repeated?