Plugging in the values from Declan's weigh-in onto the growth charts found @ http://pediatrics.about.com/cs/growthcharts2/a/percentiles.htm - we get:
At 17 months:
your child is 26.75 pounds, and that is
at the 66th percentile for weight.
your child is 31 inches, and that is
at the 19th percentile for height.
your child has a head circumference of 19.3 inches, and that is
at the 84th percentile for head circumference.