Quantity of various food items used by a restaurant during 4 months of a year (in kg).

Month →  Food Item ↓	March	April	May	June
A	220	180	270	320
B	255	320	390	420
C	280	295	280	315
D	350	310	250	280
E	308	340	350	365

What is the average quantity of food item C used during all the 4 months together?