condition mean min max ZT0-3 12.833211 12.833211 12.833211 ZT4-7 11.6859705 11.6859705 11.6859705 ZT8-11 12.315768 12.315768 12.315768 ZT12-15 15.3684725 15.3684725 15.3684725 ZT16-19 11.725805999999999 11.725805999999999 11.725805999999999 ZT20-23 13.3179005 13.3179005 13.3179005