The Senate shall be composed of 21 members who shall be chosen to hold office for 4 years. The State shall be divided into 21 senatorial districts, from each of which shall be chosen by the qualified electors thereof, 1 Senator. The terms of office of the several Senators shall be staggered so that 10 Senators shall be elected at the first biennial general election following June 30, 2011, for a term of 2 years, and 11 Senators shall be elected at such election for a term of 4 years.