GetComparisonCategoryNumAchievements

Returns the number of achievements completed by the comparison unit within a category.  
Only accurate once the INSPECT_ACHIEVEMENT_READYevent has fired following a call to SetAchievementComparisonUnit(). No longer accurate once ClearAchievementComparisonUnit() is called.
 
 
Signature:

Arguments:

• id - The numeric ID of an achievement category (number)

Returns:

• numCompleted - Number of achievements completed by the comparison unit in the category (number)