condition mean min max ZT0-3 6.6301643115 2.1200146330000003 11.14031399 ZT4-7 2.9667937699999998 2.311845403 3.621742137 ZT8-11 3.45733911275 2.937224683 3.9774535425 ZT12-15 3.403242648 3.1564784945 3.6500068015 ZT16-19 4.58108806425 3.707502121 5.4546740074999995 ZT20-23 7.83358008675 7.103135648 8.564024525499999