Only about 1.7 % of girls' first names in the United States begin with the letter Y…
This means that the initial Y is found much less frequently than average. On average, each letter appears as an initial in about 3.8 % of all girls' names, considering the 26-letter English alphabet. In fact, the letters that form initials aren’t distributed evenly – some initials are very common, while others are very rare. The most common initials among girls' names in the United States are A and S, while very few names begin with the letters U and X.