In this chapter,in order to compare the trends of juvenile delinquency in Japan with those in foreign countries,the trend of juvenile delinquency as well as the juvenile justice system and the state of its administration in France,Germany,the United Kingdom(limited to England and Wales.Hereinafter the same.),and the United States of America for the past ten years,from1994to2003,has been overviewed within the extent of the official data which we were able to obtain.
  Due to the fact that the scope of acts regarded as crime or the necessary conditions which constitute criminal acts are different,and statistics are not taken in the same way,as well as the fact that there is a difference in the age group identified as juveniles in Japan and the above-mentioned four countries,it is difficult to make an accurate comparison between the countries.However,for major crimes such as criminal offenses as well as five designated types of crime which are homicide,robbery,injury,larceny,and rape(in order to make a comparison of crime designated as these crime names in Japan,it was necessary to aggregate statistical figures for a number of crimes in the above-mentioned four countries.Therefore in this chapter these are stated as"types of crime"and the above five types of crime are stated as the"designated five types of crime")through the method of adjusting the statistical figures by the same age group as much as possible,the trends in juvenile delinquency of each country were perceived in generalities.
  Further,to help understand the actual situation of juvenile delinquency in the above-mentioned four countries,in addition to the trend in juvenile delinquency,the juvenile justice system and the state of its administration has been overviewed for each country.
  In this chapter,in reviewing the trends in juvenile delinquency of Japan and the above-mentioned four countries,due to the difference in the age regarded as juveniles,for reasons of convenience,as a general rule"juveniles"are persons under the age of18in Japan and France,from14to under the age of18in Germany,from10to under the age of18in the UK and USA,while"senior juveniles"are persons from18to under the age of20in Japan,from18to under the age of21in Germany,the UK and USA,and"adults"are persons20or over in Japan,18or over in France,21or over in Germany,the UK and USA.The phrase"population ratio of juveniles"refers to the ratio of arrested persons who are10or over to under the age of18(however,in Germany it is14or over to under the age of18)per population of100thousand,while"population ratio of senior juveniles"refers to the ratio of arrested persons who are18or over to under the age of21(however,in Japan it is18or over to under the age of20)per population of100thousand,and"population ratio of adults"refers to the ratio of arrested persons who are21or over(however,in Japan it is20or over,and in France18or over)per population of100thousand.