condition mean min max ZT0-3 9.349995 9.349995 9.349995 ZT4-7 5.21495 5.21495 5.21495 ZT8-11 6.4286449999999995 6.4286449999999995 6.4286449999999995 ZT12-15 13.48215 13.48215 13.48215 ZT16-19 15.2293 15.2293 15.2293 ZT20-23 11.71645 11.71645 11.71645