Variable calculated from the following variables:
- e2 (Number of rooms)
- hmember (Number of persons living in the HH (excluding the persons declared as living outside the HH))

Stata program:
gen hratocc = hmember/e2 if !inlist(e2, 7777, 8888, 9999)
replace hratocc=7777 if e2==7777
replace hratocc=8888 if e2==8888
replace hratocc=9999 if e2==9999