age (in years) x	age-specific survivorship lx	age-specifc fecundity* mx	lxmx	xlxmx
0-4	1.000	0	0	0
5-9	0.989	0	0	0
10-14	0.988	0.0033	0.0033	0.041
15-19	0.987	0.1278	0.1261	2.207
20-24	0.985	0.2723	0.2682	6.035
25-29	0.982	0.2770	0.2720	7.480
30-34	0.979	0.1783	0.1746	5.675
35-39	0.975	0.0655	0.0639	2.396
40-44	0.969	0.0110	0.0107	0.458
45-49	0.961	0.0005	0.0005	0.024
50-	0.948	0	0	0
		Sums	0.9193	24.316

*annual birth rates X 5 (because age-classes span 5 years) / 2 (because only half of all births are females) -- this correction is necessary because Vital Statistics of U. S. presents annual birth rates for females in 5-year age-classes!

What proportion of women survive from birth to age 45?   96%

What is the survival of women from age 20 to age 25?   0.982/0.985 = 0.997 = 99.7%

What is the mortality of women between age 20 and age 25?   1 - 0.997 = 0.003 = 0.3%

How many babies does an average (surviving) woman have in her twenties?   (0.2773 + 0.2770) X 2 = 1.1

In what age-class is fecundity highest?   25-29

What is R₀ for this population?   0.919

What is the generation time?   24.316 / 0.9193 = 26.5 years

What is the estimated proportionate annual change in numbers of this population?   = R₀^1/T = 0.997

Why is this estimate of lower than 1.017 (the proportionate annual increase in the U.S. population that we used earlier) ??

age (in years) x	age-specific survivorship lx	age-specifc fecundity* mx	lxmx	xlxmx
0-4	1.000	0	0	0
5-9	0.620	0	0	0
10-14	0.550	0	0	0
15-19	0.500	0.406	0.203	3.55
20-24	0.430	0.479	0.206	4.64
25-29	0.360	0.995	0.358	9.85
30-34	0.300	0.911	0.273	8.87
35-39	0.260	0.626	0.163	6.11
40-44	0.210	0.088	0.018	0.77
45-49	0.180	0	0	0
50-	0.150	0	0	0
		Sums	1.221	33.79

*annual birth rates (based on pregnancy rates from palpation of abdomen) converted to female births per age-class (in this case, adjusted for mortality during the age-class); annual birth rates based on palpation give nearly accurate overall birth rate (0.25 births/female aged 15-44/year)

What proportion of women live to age 45?   18%

What is the survival of women from age 20 to age 25?   0.36/0.43 = 0.837 = 83.7%

What is the mortality of women between age 20 and age 25?   1 - 0.837 = 0.163 = 16.3%

How many babies does an average (surviving) woman have in her twenties?   (0.479 + 0.995) X 2 = 2.9

In what age-class is fecundity highest?   25-29

What is R₀ for this population?   1.22

What is the generation time?   33.79/1.221 = 27.7

What is the proportionate annual change in numbers of this population?   = R₀^1/T = 1.01