题目

Are the British people Europeans? This may seem a strange question to Africans and Asians, who tend to think of all white men as Europeans．But the British, when they are in Britain, do not regard themselves as Europeans．The Europeans, to them, are those rather excitable foreigners from the other side of the English Channel, who have never learnt how to speak English．Europe is “the  Continent ”, a place full of interest for British tourists, but also the source of almost all the wars in which Britain has ever been involved．Thus , although geographically speaking Britain is part of 根据国家质量监督检验检疫局发布的《车辆驾驶人员血液、呼气酒精含量阈值与检验》(GB19522—2004)中规定车辆驾驶人员血液酒精含量：“饮酒驾车非醉酒驾车”的临界值为20 mg/100 mL；“醉酒驾车”的临界值为80 mg/100 mL.某地区交通执法部门统计了5月份的执法记录数据： 血液酒精含量 (单位：mg/100 mL) 0～20 20～40 40～60 60～80 80～100 人数 180 11 5 2 2 　　根据此数据，可估计该地区5月份“饮酒驾车非醉酒驾车”发生的频率为________．