condition mean min max ZT0-3 1.2652453125 0.52387415 2.006616475 ZT4-7 4.39921121375 3.3189720885 5.479450339 ZT8-11 5.689665652 5.56259384 5.816737464 ZT12-15 7.584897117500001 5.585280364 9.584513871 ZT16-19 15.8809073125 12.01782403 19.743990595 ZT20-23 41.373503955000004 32.028809265 50.718198645