{
  "fields": [{"id":"_id","type":"int"},{"id":"年度","type":"text"},{"id":"第１号被保険者数[人]","type":"text"},{"id":"任意加入被保険者数[人]","type":"numeric"},{"id":"被保険者総数[人]","type":"numeric"}],
  "records": [
    [1,"2013","41519",1004,42523],
    [2,"2014","41229",986,42215],
    [3,"2015","40729",1025,41754],
    [4,"2016","39468",1025,40493],
    [5,"2017","39003",982,39985],
    [6,null,null,null,null],
    [7,"平成30年度港区行政資料集　国民年金被保険者の推移","Ver201803",null,null]
]}