a,1990-01-10,2090,97.1,XA ,{a}
b,1990-11-01,2203,98.1,XA ,"{a,b}"
c,1988-11-01,2907,99.4,XB ,"{w,y}"
d,1985-05-05,2314,98.3,XB ,{}
e,1995-05-05,2236,98.2,XC ,{a}