A company's Chief Operating Officer $($COO$)$ keeps track of the mileage on her trips from her office at

corporate headquarters to the company's off$-$site manufacturing facility and its nearby suppliers. The

stem$-$and$-$leaf display of the data for one year is below.

$769$

$77114$

$78$

$7907$

$8088$

$812$

$821$

$8388$

How many trips were used in this display?