condition mean min max ZT0-3 441.511532 441.511532 441.511532 ZT4-7 665.54806 665.54806 665.54806 ZT8-11 323.5403965 323.5403965 323.5403965 ZT12-15 416.7170215 416.7170215 416.7170215 ZT16-19 639.2579840000001 639.2579840000001 639.2579840000001 ZT20-23 530.5263955 530.5263955 530.5263955