Not only were home birth not uncommon, but we know pretty much how many unattended births there were in Hawaii in 1961 as well as how many births were out of state, but still registered to Hawaiian parents. Two such births, for example, took place in the state of Washington.
Not uncommon in some circles, but by '61 they'd have been extremely uncommon for the daughter of a banker and store manager.
Could you share those numbers, as fractions of total births, or just raw numbers with the total births, I can do division if I drag out one of my slide rules. :) Ditto for out of state births.
(As it happens one the cousins of my granddaughter, born a month after she was in 2005, was a non hospital birth. But it was attended. By an ambulance attendant, somewhere along the side of the road in New Jersey. :) Fortunately, while it was the first birth he attended, it was not her first birth.)