I would say you will see a greater % of kids less than 2, although I really cannot give you an estimate. I would say that in an ambulatory setting, out of 10 patients, 2-3 would be infants (under 1 year old), 4 would be from 1-5 and the rest would run the gammut from 5 to late teens.
Think about it: most immunizations are given to this age group, there are periodic well baby checks, minor illness at older age groups can really be severe in infants, it is "prime time" for ear infections, also "prime time" for parents with developmental questions/concerns, etc.
Kids 2 and under will be a big part of your peds residency, if you decide to go into peds. There will be nursery checks on newborns, newborn checks during deliveries, circumcisions, the greatest chunk of PICU admissions falls into this age range, you will spend a lot of time in the well baby nursery and a lot more in the NICU. All this being said, it doesn't mean that this has to continue into your practice. You could choose to specialize in teenagers, an option avaliable if you choose to work at a Children's Hospital. Otherwise, if you go into peds, be prepared for tons of babies.
I really enjoy peds, although I am not going into a peds residency. I have done 4 peds rotations, at a Children's Hospital, so far and I have one more coming up (PICU, inpatient, outpatient clinic and Peds ER). This has been my experience although others might have a different view.