gistfile1.txt

var all = @"// redacted";
 
 var firstLetters = all
 .Split('\n')
 .Select(n => n.Trim().ToUpper())
 .Select(n => n.Substring(n.IndexOf(" ") + 1)[0]);
 
var counts = from l in firstLetters
  		 group l by l into g
			 select new
			 {
			 	Letter = g.Key,
				Count = g.Count()
			 };
			 
var forAll = from a in "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
			 join l in counts on a equals l.Letter into j
			 from x in j.DefaultIfEmpty()
			 orderby a
			 select new
			 {
			 	Letter = a,
				Count = x == null ? 0 : x.Count
			 };
 forAll.Dump();
 forAll.Sum(x=> x.Count).Dump();
 forAll.Where(x => x.Letter <= 'P').Sum(x=> x.Count).Dump();