How Many People Keep Their New Years Resolutions?

It was hard to find exact statistics on it. One site suggests that it's as low as 8%. I think the problem is that people make resolutions that need to last all year such as quitting smoking or losing weight. I think there would be a much higher success rate if the resolutions were more specific both in time and intent such as "I will clean out the garage in January" instead of "I will get organized". How do you think resolutions could be more successful?