  A number field is said to be a CM-number field if it is a totally imaginary
quadratic extension of a totally real number field. We define a totally
imaginary number field to be of CM-type if it contains a CM-subfield, and of
TR-type if it does not contain a CM-subfield. For quartic totally imaginary
number fields when ordered by discriminant, we show that about 69.95% are of
TR-type and about 33.05% are of CM-type. For a sextic totally imaginary number
field we classify its type in terms of its Galois group and possibly some
additional information about the location of complex conjugation in the Galois
group.
