Fix same bug that was in `frequency` command.
Fix same bug that was in `frequency` command.

Basically, we need to guard against the case when the number
of records is less than the number of jobs specified by the user.

aubergene/xsv,aubergene/xsv,BurntSushi/xsv,BurntSushi/xsv,Select-License/xsv,aubergene/xsv