condition mean min max ZT0-3 10.409496 10.409496 10.409496 ZT4-7 11.1449745 11.1449745 11.1449745 ZT8-11 10.351339 10.351339 10.351339 ZT12-15 10.234467500000001 10.234467500000001 10.234467500000001 ZT16-19 10.3817895 10.3817895 10.3817895 ZT20-23 9.027819000000001 9.027819000000001 9.027819000000001