Xiumin (99) - 11 + 88, because he first appeared in the 11th teaser
Luhan (7 or 77) - Cristiano Ronaldo’s jersey number was 7 when he played for Manchester United
Kris (00) - together with Suho’s 1, they make 100
Suho (1 or 7) - together with Kris’s 00, they make 100; 7 is the number of years he spent as a trainee
Lay (10) - he was born in October; there’s a Chinese idiom “?? ??,” literally “ten all ten beautiful,” that means “perfection"
Baekhyun (4) - He wanted to be a singer since 4th grade; the 4th grade batter is the most important one in baseball (the cleanup hitter)
Chen (21) - he was born on the 21st of September
Chanyeol (61) - his childhood nickname was Park Chanho, who’s a famous Korean baseball player with jersey number 61
D.O. (12) - he was born on the 12th of January; Exo has 12 members
Tao (68) - added together, the digits make 14, the date on which his 2nd teaser was released
Kai (88) - H is the 8th letter of the alphabet, so 88 stands for “HH” hip-hop; 88 in Morse Code also means “love and kisses”
Sehun (94) - he was born in 1994