condition mean min max ZT0-3 5.418455 4.451415 6.385495000000001 ZT4-7 6.60947 6.60947 6.60947 ZT8-11 5.107275 5.107275 5.107275 ZT12-15 0 0 0 ZT16-19 5.4986049999999995 5.4986049999999995 5.4986049999999995 ZT20-23 7.226305 7.226305 7.226305