condition mean min max ZT0-3 449.288905 449.288905 449.288905 ZT4-7 497.47283000000004 497.47283000000004 497.47283000000004 ZT8-11 763.676657 763.676657 763.676657 ZT12-15 1084.183603 1084.183603 1084.183603 ZT16-19 893.573185 893.573185 893.573185 ZT20-23 1564.986399 1564.986399 1564.986399