condition mean min max ZT0-3 3.90728 2.1830600000000002 7.10599 ZT4-7 4.164955 4.164955 4.164955 ZT8-11 3.5360050000000003 3.5360050000000003 3.5360050000000003 ZT12-15 9.440010000000001 8.751085 10.128935 ZT16-19 6.61285 6.61285 6.61285 ZT20-23 4.890855 4.890855 4.890855