condition mean min max ZT0-3 2171.654733 2171.654733 2171.654733 ZT4-7 1323.3799685 1323.3799685 1323.3799685 ZT8-11 978.2645494999999 978.2645494999999 978.2645494999999 ZT12-15 1011.435066 1011.435066 1011.435066 ZT16-19 965.0802025 965.0802025 965.0802025 ZT20-23 933.450902 933.450902 933.450902