The Senators shall be elected from districts. The General Assembly, at the first regular session convening after the return of every decennial census of population taken by order of Congress, shall revise the senate districts and the apportionment of Senators among those districts, subject to the following requirements:

1. (1) Each Senator shall represent, as nearly as may be, an equal number of inhabitants, the number of inhabitants that each Senator represents being determined for this purpose by dividing the population of the district that he represents by the number of Senators apportioned to that district;
2. (2) Each senate district shall at all times consist of contiguous territory;
3. (3) No county shall be divided in the formation of a senate district;
4. (4) When established, the senate districts and the apportionment of Senators shall remain unaltered until the return of another decennial census of population taken by order of Congress.