What is the density of yushan county?
{'header': ['English Name', 'Simplified', 'Traditional', 'Pinyin', 'Area', 'Population', 'Density'], 'page_title': 'Shangrao', 'section_title': 'Subdivisions', 'caption': 'Subdivisions', 'rows': [['Xinzhou District', '信州区', '信州區', 'Xìnzhōu Qū', '339', '416219', '1228'], ['Dexing City', '德兴市', '德興市', 'Déxīng Shì', '2101', '293202', '140'], ['Shangrao County', '上饶县', '上饒縣', 'Shàngráo Xiàn', '2240', '700266', '313'], ['Guangfeng County', '广丰县', '廣豐縣', 'Guǎngfēng Xiàn', '1378', '752939', '546'], ['Yushan County', '玉山县', '玉山縣', 'Yùshān Xiàn', '1728', '574363', '332'], ['Yanshan County', '铅山县', '鉛山縣', 'Yánshān Xiàn', '2178', '427000', '196'], ['Hengfeng County', '横峰县', '橫峰縣', 'Héngfēng Xiàn', '655', '184870', '282'], ['Yiyang County', '弋阳县', '弋陽縣', 'Yìyáng Xiàn', '1593', '353378', '222'], ['Yugan County', '余干县', '餘干縣', 'Yúgān Xiàn', '2331', '887603', '381'], ['Poyang County', '鄱阳县', '鄱陽縣', 'Póyáng Xiàn', '4215', '1296756', '308'], ['Wannian County', '万年县', '萬年縣', 'Wànnián Xiàn', '1141', '359098', '315']]}