Out of 149 days I was at work this year (low number due to taking extended vacations this past summer and being off for an extended time due to commuting accident in the fall) it broke down to:
78 days riding to work
16 driving to work due to weather (mostly high wind days wich we had an unusual number of this year)
33 driving due to appointments or meetings after work
20 driving due to being injured (hoping to be back in the saddle early next year)
2 driving due to bike needing repair

Not a great year but hoping to get back on track for 2012.