condition mean min max ZT0-3 221.395392 221.395392 221.395392 ZT4-7 247.652309 247.652309 247.652309 ZT8-11 269.077924 269.077924 269.077924 ZT12-15 290.963581 290.963581 290.963581 ZT16-19 301.187849 301.187849 301.187849 ZT20-23 302.5344215 302.5344215 302.5344215