"ts","dur","part","a","b"
100,400,0,111,"[NULL]"
500,50,0,222,"[NULL]"
600,100,0,333,"[NULL]"
900,100,0,444,"[NULL]"
100,150,1,111,444
250,50,1,111,"[NULL]"
300,100,1,111,555
400,100,1,111,666
500,50,1,222,666
600,50,1,333,666
650,50,1,333,"[NULL]"
900,100,1,444,"[NULL]"
100,400,2,111,777
500,50,2,222,777
600,100,2,333,777
900,100,2,444,777
100,400,4,111,"[NULL]"
500,50,4,222,999
600,100,4,333,"[NULL]"
900,100,4,444,"[NULL]"
100,25,5,111,1111
125,375,5,111,"[NULL]"
500,25,5,222,"[NULL]"
525,25,5,222,2222
600,100,5,333,"[NULL]"
900,100,5,444,"[NULL]"
100,400,6,111,"[NULL]"
500,50,6,222,"[NULL]"
600,100,6,333,"[NULL]"
900,100,6,444,"[NULL]"