condition mean min max ZT0-3 11.7464411925 11.672415375 11.82046701 ZT4-7 12.318883552833334 11.986675238666667 12.651091867 ZT8-11 14.97924186 14.96226297 14.99622075 ZT12-15 15.408902788333332 14.064043436666667 16.75376214 ZT16-19 16.104734405 15.19608399 17.01338482 ZT20-23 16.081603375 15.937727903333332 16.225478846666668