condition mean min max ZT0-3 14.121525 14.121525 14.121525 ZT4-7 14.2833875 14.2833875 14.2833875 ZT8-11 11.3329445 11.3329445 11.3329445 ZT12-15 12.801010999999999 12.801010999999999 12.801010999999999 ZT16-19 10.704117 10.704117 10.704117 ZT20-23 10.3503635 10.3503635 10.3503635