How do I create a file with 100 random numbers with 15 numbers on each line?

My assignment is to create a new file with 100 random numbers to a new file with 15 numbers on each line. I can get it to print out 100 random numbers, but when I try to get it to print 15 numbers per line, the program never finishes running.

import java.util.*;
import java.io.*;
public class Random100{
   public static void main(String [] args)throws IOException
   {
      PrintWriter out = new PrintWriter(new File("random.txt"));
      Random rand = new Random();
      int number, count=0, countTwo=0;
      while(count!=100)
      {
         while(countTwo<=15)
         {
        number=rand.nextInt(100)+1;
        out.print(number);
        count++;
        countTwo++;
     }
     out.println();
  }
  out.close();
  }
}