Rank Table Calc Not Working w/Null Data

I am trying to show a trend line by different ID's for a time period (let's use Jan 2019 for this example) and I would like to rank them by the amount change between a time period, Jan 27 and Jan 31. I created two calculated fields, one for the amount on Jan 27 and another for the amount on Jan 31 and then another calculated field for the amount change (which I fixed to the ID). I then used that Amount Change field as a rank table calculation to rank the IDs. This works great as long as each ID has a data point for every single day in the data but if they started in the middle of the month for example, the rank table calc no longer works. This is demonstrated by the ID F in my attached workbook and can be seen in the image below.

I mostly want to use this rank field as a filter so I can get the top/bottom N IDs but this clearly is not working. I know I could use the Top N filter using ID but I am having another issue where that is not working properly so I am trying to come up with a workaround.