condition mean min max ZT0-3 4.25744138475 3.4411112545 5.073771515 ZT4-7 4.45887324325 3.66245085 5.2552956365 ZT8-11 7.149512913 6.215854143 8.083171683 ZT12-15 6.2371982895 6.1890826389999996 6.28531394 ZT16-19 8.5337932225 7.4454259845 9.6221604605 ZT20-23 14.363045212500001 11.66708909 17.059001335