condition mean min max ZT0-3 100.731537 100.731537 100.731537 ZT4-7 55.840542 55.840542 55.840542 ZT8-11 62.483477 62.483477 62.483477 ZT12-15 90.4865085 90.4865085 90.4865085 ZT16-19 134.4023055 134.4023055 134.4023055 ZT20-23 148.798493 148.798493 148.798493