Views Groupby Date Granularity

Hi all,

I've got a View that displays content types sorted by a date field. The Date field contains month, day and year. The sort works fine.

But I'd like to group the listings by Year. I can Group by the date field, but it doesn't give me enough granularity to specify the Year, only the whole date. This creates a "group" for each day. Is there a way that I can get the granularity that I need to group by year only?

Thanks in advance.