condition mean min max ZT0-3 1.093565 0.7528855000000001 1.2826495 ZT4-7 3.1198050000000004 3.1198050000000004 3.1198050000000004 ZT8-11 1.4758385 1.4758385 1.4758385 ZT12-15 1.6534274999999998 1.297335 2.0095199999999998 ZT16-19 1.1561745 1.1561745 1.1561745 ZT20-23 0.786573 0.786573 0.786573