Most dates are complete, however some are not. In these cases, the words: after, before and circa are sometimes used, which indicates some type of estimate was used either based on a source or an educated guess. This is done to help me later in research while looking for primary or secondary sources to find the answer or another clue. My "magic" numbers based on the statistics contained within my data are as follows:
| Males | Females | |
| Age at first marriage | 25.5 years +/- 6.6 | 22.4 years +/- 6.0 |
| Age at first child | 27.6 years +/- 6.3 | 24.2 years +/- 5.4 |
| Age at last child | 34.3 years +/- 8.3 | 30.7 years +/- 7.1 |
| Age at Death | 62.3 years +/- 24.1 | 63.6 years +/- 25.9 |
In the case of using the term "circa" my aim for dates is +/- 5 years from the date shown, but will more likely be closer than that. In some cases there is only a general guess based on the source that was used to obtain a piece of information in those cases the terms used are "after" or "before." The "before" date refers, not to the date itself, but to the date when the event actually occurred sometime before this date. An example would from one of my sources, the "History of Lycoming County," by John F. Meginness which was published in 1892. In this case it shows that John Smith the son of Jesse Smith was deceased, but no date was given. I would list John's date of death as "before 1892" since the books date was 1892.