Figures & data
Table 1 Statistics on seasonal variation data on births and deaths of the Lemmer family
Figure 1 Seasonal variation in natality and mortality in the German family branch.
Notes: Data from 2,361 members were included, as collected by the ancestor program MacFamily TreeCitation30 for the German branch of the family. Shown are the number of births and deaths as normalized events per month (30 days) in the time spans of 1500–1799, 1800–2013, and 1950–2013. Significance of rhythm analysis (RA)Citation32 by Chronos-Fit is given.
Figure 2 Seasonal variation in natality and mortality in the South African family branch.
Notes: Data from 1,284 members were included as collected by the ancestor program MacFamily TreeCitation30 of the South African branch of the family. Shown are the number of births and deaths as normalized events per month (30 days) in the time spans of 1800–2000 and 1950–2000. Data from LemmerCitation23 and Lemmer and Lemmer.Citation24 No seasonal rhythm was found by rhythm analysis,Citation32 nor significant variation by chi-squared test for equal frequencies.
Figure 3 Seasonal number of weddings in the German family branch.
Notes: Monthly weddings for the time spans 1500–1799, 1800–2013, and 1950–2013. Data collected from ancestors’ files.Citation22,Citation23
Figure 4 Seasonal number of weddings in the South African family branch.
Notes: Monthly weddings for the time spans of 1800–2000 and 1950–2000. Data were collected from ancestor files.Citation24
Figure 5 Birth of first child after marriage in the German family branch.
Notes: Time span between wedding and birth of first child of the family. Data from Lemmer.Citation22
Figure 6 Birth of first child after marriage in the South African family branch.
Notes: Time span between wedding and birth of the first child. Data from Lemmer.Citation24
