Get The Difference Between 2 Date In Month And With Decimal Value For The Day Left

Is there a way to get the difference between two dates in Month. I would like decimal for the day.

EX :

First Date : 2010-12-20
Second Date : 2011-12-30

This is like 1 months and 10 days between these date.

The difference should give me : 1.33

DateTime dt = new DateTime();
dt = Convert.ToDateTime("2011-12-30"); ;
DateTime dt2 = new DateTime();
dt2 = Convert.ToDateTime("2010-12-20");
int monthDiff = System.Data.Linq.SqlClient.SqlMethods.DateDiffMonth(dt,dt2);