I believe that the dining room and cafe staff [usually staffed in part by DR wait/busy folks] will have this information.
I have been cruising since 1967 and it was hard for me to break the last night tip and handshake. Slowly, I have taken to heart what the cruise lines say about 'prepaid' or daily tipping, that it, "...insures that all wait staff will be recognized...". Then I realized how to be fair in tipping the dining room staff and the casual buffet staff? Our evenings are half in the formal dining room and the other in the buffet. I thought it might be tacky to reduce the dining room tips and then how to graciously leave something for the cafe wait person who helps in the buffet with drinks, etc., and then what is the appropriate amount?
I do let the wait staff, Restaurant Manager and Maitre 'D know that I am a repeat passenger will a few special requests. That way they know that if I may ask for a bit more, they will be taken care of for their extra efforts. This allows me to present the Dining Room staff with something extra on the last night. Sometimes we enclose a person note of thanks in their envelope. I sign the envelope, list my cabin number on the outside and seal the envelope.