condition mean min max ZT0-3 11.42745 11.42745 11.42745 ZT4-7 14.86265 14.86265 14.86265 ZT8-11 6.731325 6.731325 6.731325 ZT12-15 3.94996 3.94996 3.94996 ZT16-19 4.6625049999999995 4.6625049999999995 4.6625049999999995 ZT20-23 6.6258300000000006 6.6258300000000006 6.6258300000000006