Not only are fewer younger people (18-24) registered to vote than any other age group, but the younger registered voters themselves are less likely to vote than older registered voters.
Based on 2008 numbers, the Secretary of State reports:
•For 18-24 year olds, 18 percent of those registered took part in the primary and 68 percent voted in the General Election.
•For 25-34 year olds, it was 19 percent in the primary, 74 percent in November.
•For 35-44 year olds, 27 percent voted in primary and 82 percent in the General Election.
•For 45-54 year olds, 41 percent voted in primary and 87 percent in general.
•For 55-64 year olds, 58 percent voted in primary and 91 percent in general.
•And those 65 and older took the prize, with 72 percent voting in primary and 91 percent in general.
The Secretary of State has not yet broken down this year's primary "turnout" (I'm not sure what else to call it now that it's all vote-by-mail) by age, but they report 41 percent participation overall.