condition mean min max ZT0-3 11.828802 11.828802 11.828802 ZT4-7 12.752638999999999 12.752638999999999 12.752638999999999 ZT8-11 11.6387685 11.6387685 11.6387685 ZT12-15 10.4750625 10.4750625 10.4750625 ZT16-19 12.944037999999999 12.944037999999999 12.944037999999999 ZT20-23 12.113729 12.113729 12.113729