condition mean min max ZT0-3 6.742215 6.742215 6.742215 ZT4-7 7.868145 7.868145 7.868145 ZT8-11 9.183 9.183 9.183 ZT12-15 6.668095 6.668095 6.668095 ZT16-19 11.542649999999998 11.542649999999998 11.542649999999998 ZT20-23 7.63384 7.63384 7.63384