condition mean min max ZT0-3 142.836415 142.836415 142.836415 ZT4-7 259.772768 259.772768 259.772768 ZT8-11 380.5923805 380.5923805 380.5923805 ZT12-15 269.7003325 269.7003325 269.7003325 ZT16-19 317.304043 317.304043 317.304043 ZT20-23 207.463293 207.463293 207.463293