condition mean min max ZT0-3 0.290903796 0.13197910000000002 0.44982849199999997 ZT4-7 1.4251092415 1.147500499 1.702717984 ZT8-11 1.9576818459999998 1.6513761814999999 2.2639875105 ZT12-15 3.5066348015 2.8914616300000002 4.121807973 ZT16-19 3.49739231575 2.878837007 4.1159476244999995 ZT20-23 7.5483889065 6.1182821165 8.9784956965