condition mean min max ZT0-3 2.952495 2.9307749999999997 2.974215 ZT4-7 4.10187 4.10187 4.10187 ZT8-11 4.3543400000000005 4.3543400000000005 4.3543400000000005 ZT12-15 0 0 0 ZT16-19 5.2276299999999996 5.2276299999999996 5.2276299999999996 ZT20-23 4.45583 4.45583 4.45583