It varies from time to time depending on the above mentioned factors. I am a 27year old married man. I have 2 sons. You are lucky on two counts. Second that you are merrily married.
Most men complain that their merry making ended with marriage.
Rest assured that it is your knowledge of sex that has helped you to beget children. All the best for the future. I have one major problem. When I have sex then I become weak and lose my weight. If I do have sex daily or regularly then the condition is very critical.