condition mean min max ZT0-3 23.57965 23.57965 23.57965 ZT4-7 56.563900000000004 56.563900000000004 56.563900000000004 ZT8-11 20.0134 20.0134 20.0134 ZT12-15 6.1309249999999995 6.1309249999999995 6.1309249999999995 ZT16-19 6.036205000000001 6.036205000000001 6.036205000000001 ZT20-23 10.25874 10.25874 10.25874