Per capita expenditures for police protection for 20 cities are reported here for 1995 and 2000.

Compute a mean and standard deviation for each year, and describe the differences in expenditures for the five-year period.

City 1995 2000 A 180 210 B 95 110 C 87 124 D 101 131 E 52 197 F 117 200 G 115 119 H 88 87 I 85 125 J 100 150 K 167 225 L 101 209 M 120 201 N 78 141 O 107 94 P 55 248 Q 78 140 R 92 131 S 99 152 T 103 178