'Incidence' is an undesirable frequency of occurrence.<br/><br/>the increasing incidence of computer-related crime<br/><br/>a high incidence of crime <br/><br/><i><font color="">a high incidence of malaria in the tropics</font></i><br/><br/><i><font color="">did not expect criticism and was surprised by its incidence</font></i><br/><br/>the incidence of incidents (OK?)<br/><br/>My question is, do you ever say 'incidences'?<br/><br/>Thanks.<br/>