Each state of the United States selects two senators to represent their states in the United States Senate. In 1913, the 17th Amendment[?] to the United States Constitution provided for the direct popular election of senators; prior to this, senators were selected by state legislatures.
... 18 to 24, 34.6% from 25 to 44, 19.4% from 45 to 64, and 10.6% who are 65 years of age or older. The median age is 34 years. For every 100 females there are 102.8 males. ...