condition mean min max ZT0-3 10.164766666666667 3.4470650000000003 14.65185 ZT4-7 4.368415000000001 4.368415000000001 4.368415000000001 ZT8-11 3.518355 3.518355 3.518355 ZT12-15 4.521175 3.129045 5.913305 ZT16-19 3.607705 3.607705 3.607705 ZT20-23 3.65939 3.65939 3.65939