condition mean min max ZT0-3 5.18283 5.18283 5.18283 ZT4-7 4.04717 4.04717 4.04717 ZT8-11 4.291575 4.291575 4.291575 ZT12-15 5.2496100000000006 5.2496100000000006 5.2496100000000006 ZT16-19 7.321226666666667 7.321226666666667 7.321226666666667 ZT20-23 8.77563 8.77563 8.77563