sales	period	quarter	year
10	1	winter	1
31	2	spring	1
43	3	summer	1
16	4	fall	1
11	5	winter	2
33	6	spring	2
45	7	summer	2
17	8	fall	2
13	9	winter	3
34	10	spring	3
48	11	summer	3
19	12	fall	3
15	13	winter	4
37	14	spring	4
51	15	summer	4
21	16	fall	4