On SPSS I need to make a new variable that can calculate and average number per thousand of a state. How would I be able to go about doing this? The cities of each state are listed as seen below.

Police Salary Dataset.sav [DataSet1] - IBM SPSS Statistics Data Editor OO . . . .. .. .... + Name Type Width Decimals Label Values Missing Columns Align Measure Role 1 BT Input city String 17 C None None Left Nominal Numeric 8 0 None None 8 Right Scale Input N Pop 3 8 Input officers Numeric 8 0 None None Right Scale 8 0 None None 12 Right Scale Input 4 minsalary Numeric 5 maxsalary Numeric 0 None None 14 Right Scale Input 00 6 State Numeric 8 {1, NY}... ... None 10 Right Nominal Input 7 8 9 10