How To Use Conditional Icons To Text Column

I like to mark names of persons who have done consecutively well in last two years with green circle and those who have not with red circle using Icon sets. I have created 4 columns and filled 1st with names (Text), and other 3 columns are filled with their output scores (Numbers) over last three years (2010-12). Like to highlight those names who have done well in last two years (2011-12) as compared to the third year (2010).

For example:
Names Score 2012 Score 2011 Score 2010
John 168 153 144 (should mark with green circle)
Steve 201 182 181 (should mark with green circle)
Mary 98 102 110 (should mark with red circle)