Table 1. Distribution of the relative frequencies of the population with brucellosis based on the studied variables .

Variable	2009		2010		2011		2012		2013		2014		2015		2016		2017
	Number	Percent	Number	Percent	Number	Percent	Number	Percent	Number	Percent	Number	Percent	Number	Percent	Number	Percent	Number	Percent
Gender
Male	4876	55.1	5811	55.4	7246	56.9	9238	57.6	11446	59.9	11869	58.8	11556	58.4	8970	58.4	9157	57.7
Female	3969	44.9	4674	44.6	5501	43.1	6360	39.7	7349	38.5	8327	41.2	8247	41.6	6384	41.6	6705	42.3
Age
<15	1153	13	1528	14.6	1758	13.8	2173	13.6	2585	13.5	2738	13.6	2397	12.1	1811	11.8	1915	12.1
16 - 24	182	20.7	2098	20	2545	19.9	2960	18.5	3449	18.1	3383	16.8	2910	14.7	2036	13.3	1916	12.1
25 – 44	2965	33.5	3467	33.1	4332	33.9	5447	34	6511	34.1	7701	38.1	7696	38.9	5889	38.4	6063	38.2
45 - 54	1370	15.5	1590	15.2	1938	15.2	2126	13.3	2585	13.5	2935	14.5	3152	15.9	2579	16.8	2639	16.6
55<	1530	17.3	1802	17.2	2192	17.2	2509	15.6	2958	15.5	3439	17	3648	18.4	3039	19.8	3329	21
Residential area
Rural	6898	78	8099	77.2	10250	80.3	12472	77.8	14482	75.8	15799	78.2	15135	76.4	11404	74.3	1879	74.9
Urban	1947	22	2386	22.8	2515	19.7	3252	20.3	4070	21.3	4214	20.9	4418	22.3	3464	122.6	3667	23.1
Nationality
Iranian	8785	99.3	10395	99.1	12631	66.1	15877	83.1	18934	99.1	20022	99.1	19643	97.3	15212	99.1	15660	98.7
Afghan	58	0.7	86	0.8	130	0.7	157	0.8	165	0.9	165	0.8	145	0.7	129	0.8	181	1.1
Pakistani	1	0	2	0	1	0	-		2	0	-		-		-		12	0.1
Iraqi	1	0	2	0	2	0	1	0	-		6	0	10	0	7	0	-
History of contact with livestock
No	2248	25.4	1896	18.1	2047	16	2334	14.6	2889	15.1	4052	20.1	2436	12.3	2177	14.2	2585	16.3
Yes	6179	69.9	7929	75.6	10427	81.7	12392	77.3	14664	76.8	16144	79.9	15559	78.6	11721	76.3	11915	75.1
History of livestock vaccination
Yes	2301	26	5112	48.8	7153	56	8459	52.8	10405	54.5	7393	36.6	7340	37.1	5136	33.51	5380	33.9
No	814	9.2	2533	24.2	2968	23.3	3881	24.2	4672	24.5	12803	63.4	5168	26.1	3648	23.8	3799	24
Unclear	18	0.2	-		-		616	3.8	997	5.2	-		2852	14.4	2789	18.2	3079	19.4
History of consuming unpasteurized dairy products
Milk	3516	39.8	3244	30.9	4317	33.8	219	1.4	30501	18.3	4276	21.21	5914	29.9	4459	29	4756	30
Cheese	1063	12	1205	11.5	1403	11	39	0.2	1296	6.8	1310	6.5	1587	8	1162	7.6	1168	7.4
Whipped cream	69	0.8	68	0.6	113	0.9	5	0	95	0.5	44	0.2	88	0.4	59	0.4	69	0.4
Butter	38	0.4	59	0.6	92	0.7	4	0	78	0.4	97	0.5	104	0.5	75	0.5	59	0.4
Colostrum	91	1	160	1.5	190	1.5	7	0	225	1.2	551	2.7	299	1.5	196	1.3	248	1.6
Kaymak	95	1.1	264	2.5	138	1.1	48	0.3	170	0.9	153	0.8	123	0.6	166	1.1	225	1.4
Milk and cheese	3122	35.3	3748	35.7	4410	34.5	284	1.8	4113	21.5	7407	36.7	6346	32	4918	32	5058	31.9
Ice cream	45	0.5	87	0.8	115	0.9	5	0	117	0.6	155	0.8	202	1	139	0.9	246	1.6
None	174	2	-		-		-		-		-		-		-		-
Unclear	231	2.6	-		-		-		-		-		39	0.2	-		33	0.2
Type of contact with livestock during the last 18 months
Keeping the animal near one’s residential area	304	3.4	1774	16.9	5617	44	9362	58.4	12157	63.6	10382	51.4	13483	68.1	9666	63	4859	30.6
Contact with live animals	3756	42.5	3206	30.6	1447	11.3	1194	7.4	2235	11.7	3217	15.9	13837		1658	10.8	5724	36.1
Contact with birth secretions and/or the aborted fetus	682	7.7	1210	11.5	2121	16.6	12.6	7.5	-		-		-		-		34	0.2
Slaughtering the animal	100	1.1	659	6.3	887	6.9	380	2.4	-		-		326	1.6	257	1.7	1128	7.1
Contact with the animal corpse and its secretions after its slaughtering	507	5.7	708	6.8	42	0.3	56	0.3	305	1.6	1999	7.9	218	1.1	36	0.2	69	0.4