condition mean min max ZT0-3 6.115605 5.80712 6.42409 ZT4-7 4.33149 4.33149 4.33149 ZT8-11 5.65738 5.65738 5.65738 ZT12-15 0 0 0 ZT16-19 8.349995 8.349995 8.349995 ZT20-23 7.670635000000001 7.670635000000001 7.670635000000001