<P> By comparison, what is now the territory of China experienced 0.1 per cent annual growth from 1 CE to 1800 CE . After population decline following the disintegration of the western half of the Roman state in the fifth and sixth centuries, Europe probably re-attained Roman - era population totals in the twelfth and thirteenth centuries and, following another decline associated with the Black Death, consistently exceeded them after the mid-15th century . </P> <P> There are no reliable surviving records for the general demography of the Roman Empire . There are no detailed local records, such as underlie the demographic study of early modern Europe, either . Large numbers of impressionistic, moralizing, and anecdotal observations on demography survive from the literary sources . They are of little use in the study of Roman demography, which tends to rely instead on conjecture and comparison, rather than records and observations . </P> <P> When the high infant mortality rate is factored in (life expectancy at birth) inhabitants of the Roman Empire had a life expectancy at birth of about 25 years . However, when infant mortality is factored out, life expectancy is doubled to the late - 50s . If a Roman survived infancy to their mid-teens, they could, on average, expect near six decades of life, although of course many lived much longer or shorter lives for varied reasons . Although this figure relies more on conjecture than ancient evidence, which is sparse and of dubious quality, it is a point of general consensus among historians of the period . It originates in cross-country comparison: given the known social and economic conditions of the Roman Empire, we should expect a life expectancy near the lower bound of known pre-modern populations . Roman demography bears comparison to available data for India and rural China in the early 20th century, where life expectancies at birth were also in the low 20s . </P> <P> About 300 census returns filed in Egypt in the first three centuries CE survive . R. Bagnall and B. Frier have used them to build female and male age distributions, which show life expectancies at birth of between 22 and 25 years, results broadly consistent with model life tables . Other sources used for population reconstructions include cemetery skeletons, Roman tombstones in North Africa, and an annuities table known as "Ulpian's life table". The basis and interpretation of these sources is disputed: the skeletons cannot be firmly dated, the tombstones show non-representative sample populations, and the sources of "Ulpian's life table" are unknown . Nonetheless, because they converge with low Roman elite survival rates shown in the literary sources, and because their evidence is consistent with data from populations with comparably high mortality rates, such as in 18th century France, and early 20th century China, India, and Egypt, they reinforce the basic assumption of Roman demography: that life expectancies at birth were in the low 20s . </P>

What was the average life expectancy in the roman empire