condition mean min max ZT0-3 110.826389 110.826389 110.826389 ZT4-7 189.383893 189.383893 189.383893 ZT8-11 237.77696550000002 237.77696550000002 237.77696550000002 ZT12-15 249.6623825 249.6623825 249.6623825 ZT16-19 181.372116 181.372116 181.372116 ZT20-23 109.594145 109.594145 109.594145