1.   They track the number of airport arrivals and departures.

2.   And track the number of unopened e-mails.

3.   A spokesman for the Internal Revenue Service said the agency had not tracked the number of taxpayers who received the credit.

4.   After calling up on a computer screen a package tracking form, a customer types in his or her bill tracking number.

5.   After the hearing, DiBrienza said he would continue to push the Giuliani administration to track the number of workfare participants who later return to the welfare rolls.

6.   All game long, it tracks the number of pitches thrown, as well as the type and speed of the last pitch.

7.   But in most cases, this data is limited to tracking the number of times a single file on a Web site is called up.

8.   CUNY does not track the number of students who transfer from community colleges to four-year colleges, and graduate.

9.   Delta Air Lines said it does not track numbers of unaccompanied minors.

10.   For the first time since the Census Bureau began tracking the numbers, families in which both parents are working have become the majority among married couples with children.