Table 4.

Value	Sleep (hours/night)
10	7 to 9
9	6.5 to 7 or 9 to 10
8	6 to 6.5 or 10 to 11
7	5.5 to 6 or 11 to 12
6	5 to 5.5 or 12 to 13
5	4.5 to 5 or 13 to 14
4	4 to 4.5 or 14 to 15
3	3.5 to 4 or 15 to 16
2	3 to 3.5 or 16 to 17
1	Less than 3 or More than 17

Sleep index.