condition mean min max ZT0-3 22.21025969 14.21224514 30.20827424 ZT4-7 66.6798208125 59.927250815 73.43239081 ZT8-11 142.92960576750002 115.72786698500002 170.13134455000002 ZT12-15 95.61276397 53.263033225 137.962494715 ZT16-19 34.271270465 30.8281111 37.71442983 ZT20-23 14.783479750999998 11.422695397 18.144264104999998