Text file shows 1 random number repeating instead of different numbers vb.net

Create textfile populated with random numbers. Number of random numbers to be generated received from inputbox

        //write to textfile
        StreamWriter outputFile;

        try
        {
            outputFile = File.CreateText("randomNumbers.txt"); //open

            //declare and assign variables
            int randomNumbersInput = int.Parse(txtNum.Text);
            


            for(int k = 0; k< randomNumbersInput; k++)
            {
                int randNumber;
                Random rand = new Random();
                randNumber = rand.Next(100 + 1);

                outputFile.WriteLine(randNumber);//process
            }
            outputFile.Close(); //close file

            MessageBox.Show("File saved successfully");