How often do I need to go about repacking the hubs?

Shimano DuraAce C24 hubs, about 1 year old, 5000 miles. Bike is only used in sunny conditions, and never sees rain or any gravel riding. I'm at about 8k mi on the chain, and its just now starting to show any wear.

I'm inclined to give the hubs another year or so before worrying about, but was wondering what other people's opinions.