condition mean min max ZT0-3 10.829067 10.829067 10.829067 ZT4-7 11.855439 11.855439 11.855439 ZT8-11 11.959984 11.959984 11.959984 ZT12-15 9.917808 9.917808 9.917808 ZT16-19 9.8203365 9.8203365 9.8203365 ZT20-23 12.066194 12.066194 12.066194