Need help with formulae for calculating total experience in years and months. Stumped. Please help.

[xoenix]

I am by no means an expert user in Excel, so I'm asking for help. Below is a link to a worksheet. On this worksheet there are 12 years, separated into months. When reviewing a candidate's experience, the user would simply highlight a particular month (highlighted in green). After all experience is highlighted, user should be able to click a button to auto-calculate the experience totals. There are 7 experience boxes that need formulae:

1. Total with the condition of at least 3 years experience (36 months) in the past 10 years.
2. Total with the condition of at least 1.5 years experience (18 months) in the past 7 years.
3. Total with the condition of at least 1 year experience (12 months) in the past 3 years.
4. Total with the condition of at least 6 months experience in the past 18 months.
5. Total with the condition of at least 3 months experience in the past 12 months.
6. Total experience in years. (Total months highlighted in green on all calendars divided by 12 months in a year - rounded down).
7. Total experience in months. (Total months remaining after #6 - essentially the remainder of months that weren't enough to define a full year.

Need a button to calculate these 7 totals (totals are calculated by the number of months highlighted in green; the first 5 of which have conditions that must be met first to display totals). And then another button to reset the calendars (to remove all green highlights) and to reset all totals to zero.

Please help. I am completely stumped here.

Link to the worksheet: https://drive.google.com/file/d/0B__M8PD8thIENVhrWC1ncWNzXzg/view?usp=sharing