Consistent? That is not a trend. Look for general trend. If you do plotting, you see this http://chem.libretexts.org/@api/deki/files/1193/=Ionization_Energy_Graph_IK.png?revision=1
Of course, I'd be happy to check back on a few questions for you. To clarify, you mentioned that the first 1 or 2 digits in each number represent the family number, and that the numbers do not follow a consistent trend. Please provide me with the specific questions you would like me to review, and I will do my best to assist you further.
