Definition of headcounts:
(n) :
The number of people present in a group or employed by a company.
(n) :
The act of counting how many people are present in a group.
(n) :
More generally, a consideration of a company's appropriate staffing level based on some larger context. (Generally used adjectivally.)
(n) :
By extension, one slot in a workgroup, filled or to be filled by one person.