Before congestion elimination
        +-----------------------------------------------------------+
        |                *                            ** *   ** ** *|
      20|                *                     *      **** * ** ** *|
        |*      *       **     * **       **  **** * ***** *********|
        |*   *  * *   * **** ****** *  ** *** **********************|
      15|* * * ** *  ** **** ********* *****************************|
        |* * ******  ******* ********* *****************************|
  CD(%) |* ********* ******* ***************************************|
      10|* ********* ***********************************************|
        |*********** ***********************************************|
        |***********************************************************|
       5|***********************************************************|
        |***********************************************************|
        |***********************************************************|
       0+-----------------------------------------------------------+
           0            0.5            1            1.5            2

                     After congestion elimination
       +-----------------------------------------------------------+
       |                                                           |
     20|                                                           |
       |                                                           |
       |                                                           |
     15|                                                           |
       |                                                           |
 CD(%) |                                                           |
     10|                                                           |
       |                                                           |
       |                                                           |
     5 |                                                           |
       |                                                           |
       |        *        **  * *  *  **   *  **                 *  |
     0 +-----------------------------------------------------------+
        0            0.5            1            1.5            2
                         Link Number(*10000)