new_contents: char_map = {
      'a': 3,
      'b': 6,
      'c': 9,
      'd': 12,
      'e': 15,
      'f': 18,
      'g': 21,
      'h': 24,
      'i': 27,
      'j': 30,
      'k': 33,
      'l': 36,
      'm': 39,
      'n': 42,
      'o': 45,
      'p': 48,
      'q': 51,
      'r': 54,
      's': 57,
      't': 60,
      'u': 63,
      'v': 66,
      'w': 69,
      'x': 72,
      'y': 75,
      'z': 78,
      ' ': 81,
      '.': 84,
      '!': 87,
      '?': 90,
      'EOC': 93,  # End of Character value
      'EOF': 96  # End of String value
  }
  
subject: Create mapping of characters to percentage values