For the first show of Season 4, probably later in the year:

Dan - 27 shows (replaced Simi)
Anna - 26 shows (replaced Denise)
Matt - 24 shows (replaced Sonia)
Sophie - 20 shows (replaced Uche)
Yolanda - 19 shows (replaced Asiya)
Michael - 18 shows (replaced Mark)
Jeff - 17 shows (replaced Janet)
Kushy - 16 shows (replaced Wendy)
Liam - 15 shows (replaced Becca)
Jade W - 13 shows (replaced Hunika)
Ell - 12 shows (replaced Yahya)
Jordan - 11 shows (replaced Helen)
Harry - 10 shows (replaced Ty)
Takea - 9 shows (replaced Rachel)
Leah - 8 shows (replaced Kem)
Emma - 7 shows (replaced Dave)
John - 6 shows (replaced Jade)
Geri - 5 shows (replaced Kez)
Jade L - 4 shows (replaced Jovan)
Sandra - 3 shows (replaced Lindsey)
Kiran - 2 shows (replaced Conal)
Whoever replaces Stephen - 1 show