Looping through an array?

Okay, sorry, I put together a really simple code. So in my code, int startingPoint will change depending on some other things so I want to be sure that when startingPoint is greater than 9, that it will loop the array back to [0] and add 1 to that. Right now, my program just crashes when I have a starting number of 10 or greater.

Here is the code:

int[] myArray = new int [14];
int startingAmount = 4; //initial value in each index
int startingPoint = 10; //starting index

void initialNumbers()
{
  for (int i = 0; i < myArray.length; i ++)
  {
    myArray[i] = startingAmount; //sets all to starting amount
  }
}

void addNumber()
{
  for (int i = 0; i < startingAmount+1; i ++)
  { 
    myArray[startingPoint+i] ++;
  }
  myArray[startingPoint] = 0;
}

void setup()
{
  initialNumbers();
  addNumber(); 
}