condition mean min max ZT0-3 3.3615725000000003 2.9851400000000003 3.7380050000000002 ZT4-7 5.531415 5.531415 5.531415 ZT8-11 6.1711849999999995 6.1711849999999995 6.1711849999999995 ZT12-15 0 0 0 ZT16-19 4.538845 4.538845 4.538845 ZT20-23 5.898475 5.898475 5.898475