Conditional Average-three Columns In My Worksheet

I have three columns in my worksheet.

Column 1 reports the name of three people, John , George and Jim, column 2 the year for which they are paid (e.g. 2002, 2003 etc) and column 3 the amount of money they received each year (e.g. John received 18$ in 2005, $15 in 2004 and 11$ in 2003). I need a function to give me the average salary earned by each of these people in the period 2003-2004 e.g. John earned $15 in 2004 and $11 in 2003, so the average value is 13. Is there a function to do it automatically (so taking the conditional average---average for john given that year is 2004 or 2005)?

I want this average to be in column 5 (column 4 will contain the names john, george and jim)