Can you use dataview to subtract a number from yesterday?

What I’m trying to do

I use a daily note and I have a log entry that looks like this:

log:: #biz/earnings 5600.65

Each day I am logging the lifetime earnings - what I would like to know is the daily earnings, ie today’s number minus yesterday’s.

Is there a way to do this in dataview?

Things I have tried

TABLE
WITHOUT ID
link(Source, dateformat(date(Source), "yyyy-MM-dd")) as "",
rows.Columnname as "Lifetime", length(rows) as "Daily Earnings"
FROM !"Templates"
FLATTEN log as Columnname
WHERE contains(Columnname, "#biz/earnings")
GROUP BY file.name as Source
SORT rows.file.day DESC