condition mean min max ZT0-3 12.058953 12.058953 12.058953 ZT4-7 11.358799 11.358799 11.358799 ZT8-11 10.941545 10.941545 10.941545 ZT12-15 11.980079 11.980079 11.980079 ZT16-19 9.919796999999999 9.919796999999999 9.919796999999999 ZT20-23 11.340809 11.340809 11.340809