How does the score work?

How does the score work? My score was 256.9821 then I entered 5 bills and it went up to 282.5110 and now, 2 days later, no hits no action or anything, my score is 276.9782. What's up with the score? How does it go up/down?
Thanks!

If you want your score to remain up you have to enter at least one note per day…every day you don't enter a note your score goes down…If you don't enter any notes for long enough you score will go into the negative.. Hope that helps…