As recently as 1960 [1] their fertility rate was above 6. The neat thing too is that we can actually fill out the missing data perfectly due to the fact that the relative population sizes will always be driven entirely by fertility rates. A fertility rate of six means each older group will be exactly 1/3rd as large as each younger group, similar to how a fertility rate of 1 means each older group will be exactly twice as large as the younger group.

So here is what the table looks like if we assume that Year 0 was the final year of 6 fertility:

(148) Year 0: 4 sixties, 11 forties, 33 twenties, 100 newborns,

(194) Year 20: 11 sixties, 33 forties, 100 twenties, 50 newborns

(208) Year 40: 33 sixties, 100 forties, 50 twenties, 25 newborns

(187) Year 60: 100 sixties, 50 forties, 25 twenties, 12 newborns

(93) Year 80: 50 sixties, 25 forties, 12 twenties, 6 newborns

(46) Year 100: 25 sixties, 12 forties, 6 twenties, 3 newborns

(23) Year 120: 12 sixties, 6 forties, 3 twenties, 1 newborn

[1] - https://fred.stlouisfed.org/series/SPDYNTFRTINKOR