Calculating the last line of Table 10.2, "Vaccinated by 12 months of age", is complicated, particularly given the footnote you mentioned in your second question. This footnote means that for those children who do not have a health card, or who have a health card where the date or part of the date is missing, the date is imputed. It is assumed that the proportion of children with a missing date who received a vaccine in time is equal to the proportion of children who received that vaccine in time and have complete information. The imputed values for specific cases have a random component and are not easily replicated. See the Guide to DHS Statistics for examples (e.g. on page 16) of imputation procedures when dates are incomplete.