condition mean min max ZT0-3 10.562394 10.562394 10.562394 ZT4-7 11.935297 11.935297 11.935297 ZT8-11 11.753571 11.753571 11.753571 ZT12-15 11.7193615 11.7193615 11.7193615 ZT16-19 11.1743905 11.1743905 11.1743905 ZT20-23 11.7403485 11.7403485 11.7403485