Kathryn: Baker is the 23rd retirement. And here is the (I hope final) list:

Baker, Cubin, Doolittle, Everett, Ferguson, Hastert, Hobson, Hunter, Jindal, LaHood, McCrery, Pearce, Peterson, Pickering, Pryce, Ramstad, Regula, Renzi, Saxton, Tancredo, Weller, Wicker, Wilson (NM).