(a) The House of Representatives and the Senate shall be reapportioned and redistricted on the basis of population during the biennial session after the taking of each decennial census of the United States, or after a census taken for the purpose of such reapportionment under the authority of this State.
(b) The standard for creating districts for the election of Representatives to the General Assembly shall be to form representative districts with minimum percentages of deviation from the apportionment standard for the House of Representatives. The standard for creating districts for the election of Senators on a county basis to the General Assembly shall be to form senatorial districts with minimum percentages of deviation from the apportionment standard for the Senate. The representative and senatorial districts shall be formed consistent with the following policies insofar as practicable:
(1) preservation of existing political subdivision lines;
(2) recognition and maintenance of patterns of geography, social interaction, trade, political ties, and common interests;
(3) use of compact and contiguous territory.