condition mean min max ZT0-3 12.935287 12.935287 12.935287 ZT4-7 13.8101685 13.8101685 13.8101685 ZT8-11 13.2637755 13.2637755 13.2637755 ZT12-15 11.641288 11.641288 11.641288 ZT16-19 13.949363 13.949363 13.949363 ZT20-23 12.6811215 12.6811215 12.6811215