Top  High  Mid  Low  NA  ??? 
  50    372    2,141    14,517    29,453    46  
Need: A measure of a subject's importance, regardless of its quality
Top ((top-importance)) Subject is a must-have for a print encyclopedia.
High ((high-importance)) Subject is exceptionally important.
Mid ((mid-importance)) Subject contributes a depth of knowledge.
Low ((low-importance)) Subject fills in important details.
NA ((NA-importance)) Subject importance is not applicable.