为什么在给定代码的指定限制之后没有插入空格?

我想在字符串中每隔34个字符插入一个空格

public string MySplit()
{
 string SplitThis = "aaaaaaaaaaaa"; // assume that string has more than 34 chars
 string[] array = new string[SplitThis .Length / 34];
 for (int i = 1; i <= array.Length; i++)
 {
  SplitThis .Insert(i * 34, " ");
 }
 return SplitThis;
}