condition mean min max ZT0-3 15.0317 15.0317 15.0317 ZT4-7 11.91405 11.91405 11.91405 ZT8-11 12.061350000000001 12.061350000000001 12.061350000000001 ZT12-15 12.749649999999999 12.749649999999999 12.749649999999999 ZT16-19 15.860499999999998 15.860499999999998 15.860499999999998 ZT20-23 20.271949999999997 20.271949999999997 20.271949999999997