condition mean min max ZT0-3 11.074471 11.074471 11.074471 ZT4-7 12.956149 12.956149 12.956149 ZT8-11 11.4028285 11.4028285 11.4028285 ZT12-15 10.141269000000001 10.141269000000001 10.141269000000001 ZT16-19 10.9664275 10.9664275 10.9664275 ZT20-23 12.558267 12.558267 12.558267