A conservation group recorded the freshwater volume (in units of cubic kilometers) stored in six regional aquifers:
Region A: $2,500$
Region B: $8,000$
Region C: $11,200$
Region D: $1,750$
Region E: $3,300$
Region F: $4,900$
Would it make sense to display these data points in a pie chart? If so, what is the whole used for the pie chart?