In the 1910 census, I have a family headed by Elias Riback (b. 1876), with wife Sophia (b. 1873) and children Annie (b. 1898), Harry (b. 1902), Bessie (b. 1904), David (b. 1906), and Bernard (b. 1908).
The 1920 census is consistent with this:
In the 1930 census, I find Ellis Ribeck (b. 1875), with wife Sophia (b. 1873), and children David (b., 1907) and Bernhardt (b. 1909). This is reasonably consistent.
In the 1910 census, the couple is reported to have been married for 13 years, placing the date of marriage in 1897, the year before the birth of the first child. Sophia is also listed as having five children, all living, which accounts for the entire family in 1910. So far, so good. In the 1930 census, however, Ellis's age at first marriage is listed at 22 (marriage date: 1899), while Sophia's is given at 33 (marriage date: 1906). While the families match on all other points, I am at a loss as to how to explain the discrepancy.
I also don't know who reported these numbers to the census taker. How is that information recorded in the 1930 census (if at all)? Finally, there is a notation "al" between the names of the two sons (David and Bernhardt). What does that mean?