[en] By using contingency table evaluation Mayaud's zz indices of 1868-1967 are converted into six classes based on the Ap index. Five of the divisions are for days when the geomagnetic Ap intensity was = or > 15. The published Ap values of 1868-1976 are also converted into these same class divisions. These data provide a 109-year history of the geomagnetic field for active- or storm-day conditions. An analysis of the 109-year record suggests that coronal holes have occurred in each of the last 10 solar cycles. Though coronal holes predominantly appear in the declining years of a solar cycle, they may appear throughout a cycle. In addition the study analyzes monthly, annual, and solar cycle distributions and predicts a course for solar cycle 21