condition mean min max ZT0-3 12.487487 12.487487 12.487487 ZT4-7 12.271918 12.271918 12.271918 ZT8-11 14.197116000000001 14.197116000000001 14.197116000000001 ZT12-15 11.827551 11.827551 11.827551 ZT16-19 12.635655499999999 12.635655499999999 12.635655499999999 ZT20-23 11.714843 11.714843 11.714843