Trend Analysis/Count different categories

Please review attached spreadsheet. Is there a formula to calculate a trend. I am trying to calculate a trend at the end of the year (second tab)

Also I wanted to count the HR and Employee Relations together and Marketing and IT together.

If I want to highlight everything due on 1/31/2018, how can i put a condition. Is there a formula that will go up or down when the appraisals increase or decrease the next month.
Thank you.