1) Trends in sweetpotato demand, from a food-supply perspective

Year	Domestic production 1000 t	Trade 1000 t		Domestic demand 1000 t							Net food (kg/person/year)
		Import	Export	Total	Feed	Seed	Starch-related products	Loss	Gross food		Total
										Processed food		Processed food
1960	6,277	0	0	6,277	1,463	250	2,900	138	1,526	53	14.7	0.6
1965	4,955	0	0	4,955	1,251	204	2,621	86	793	20	7.3	0.2
1970	2,564	0	0	2,564	781	102	1,104	106	471	11	4.1	0.1
1975	1,418	0	0	1,418	333	72	418	62	533	39	4.3	0.4
1980	1,317	0	0	1,317	230	70	453	60	504	40	3.9	0.3
1985	1,527	0	0	1,527	144	66	603	71	643	60	4.8	0.5
1990	1,402	7	0	1,409	84	53	503	69	700	73	5.0	0.6
1991	1,205	2	0	1,207	98	46	392	65	606	65	4.4	0.6
1992	1,295	3	0	1,298	103	46	390	60	699	81	5.0	0.7
1993	1,033	4	0	1,037	57	42	277	41	620	67	4.4	0.6
1994	1,264	2	0	1,266	98	47	363	60	698	88	5.0	0.7
1995	1,181	1	0	1,182	68	46	368	47	653	94	4.7	0.8
1996	1,109	3	0	1,112	54	44	305	49	660	92	4.7	0.7
1997	1,130	6	0	1,136	47	40	349	31	669	95	4.8	0.7
1998	1,139	5	0	1,144	48	36	380	34	646	111	4.6	0.8

Source:

Food Balance Sheet, the Ministry of Agriculture, Forestry and Fisheries. Figures for processed food are provided by the Ministry's Upland Crop Division based on reports from prefectures.