Only about 2.4 % of boys' first names in the United States begin with the letter Z…
This means that the initial Z is represented below average: According to this, each letter (given 26 letters in the alphabet) would appear as an initial in about 3.8 % of all boys' first names. Of course, first letters aren't (exactly) evenly distributed as initials: On the contrary, some initials are especially common, while others are really rare. The most common initials among boys' first names in the United States are J and A, while fewer
boys' names begin with the letters U and X.