condition mean min max ZT0-3 5.172739999999999 4.5363 5.80918 ZT4-7 6.1715 6.1715 6.1715 ZT8-11 6.19918 6.19918 6.19918 ZT12-15 0 0 0 ZT16-19 7.90349 7.90349 7.90349 ZT20-23 7.42087 7.42087 7.42087