condition mean min max ZT0-3 950.463054 950.463054 950.463054 ZT4-7 918.006658 918.006658 918.006658 ZT8-11 1025.0741125 1025.0741125 1025.0741125 ZT12-15 1030.6317225 1030.6317225 1030.6317225 ZT16-19 1145.0675295 1145.0675295 1145.0675295 ZT20-23 1001.2009615 1001.2009615 1001.2009615