Birth, death, and migration statistics relate to population movement. Statistics of births and of immigration show population increment. Statistics of deaths and of emigration show population decrement. Statistics have Suffered in reputation because of the seeming truth of the trite statement that one can prove anything by figures. In reality figures are but evidence upon which conclusions may be based. If the evidence is faulty and the faults are not perceived, errors in judgment may result. But this is true of all evidence upon which opinions are based and is no more true of figures and statistics than it is of other kinds of evidence.