condition mean min max ZT0-3 3616.945835 3616.945835 3616.945835 ZT4-7 4499.0923615 4499.0923615 4499.0923615 ZT8-11 4023.1716435 4023.1716435 4023.1716435 ZT12-15 4260.6543995 4260.6543995 4260.6543995 ZT16-19 2802.1141845 2802.1141845 2802.1141845 ZT20-23 2520.234807 2520.234807 2520.234807