condition mean min max ZT0-3 20.982348 20.982348 20.982348 ZT4-7 23.171470499999998 23.171470499999998 23.171470499999998 ZT8-11 22.72247 22.72247 22.72247 ZT12-15 23.5281465 23.5281465 23.5281465 ZT16-19 14.714542999999999 14.714542999999999 14.714542999999999 ZT20-23 15.871508500000001 15.871508500000001 15.871508500000001