condition mean min max ZT0-3 1.881945 1.881945 1.881945 ZT4-7 1.0696965 1.0696965 1.0696965 ZT8-11 1.555235 1.555235 1.555235 ZT12-15 3.1794200000000004 3.1794200000000004 3.1794200000000004 ZT16-19 4.20138 4.20138 4.20138 ZT20-23 4.156465000000001 4.156465000000001 4.156465000000001