1.14.4 How to make custom experience fit boss bars?

So I'm trying to make it so that the boss bars show the current experience of the player.

For example if the player is level 1 the max experience will be 200 until level 2.

So how can I make it so that the progress bar sets the progress of the player experience?

This is what I got so far:

Code (Text):

    public void progressBarExperience(Player p) {
        int playerLevel = Experience.getLevel(p);
           switch(playerLevel) {
          case 1:
              double experience = Experience.getExperience(p) * 1 / 200;
              bar.setProgress(experience);
              break;
          case 2:
              double experience1 = Experience.getExperience(p) * 1 / 400;
              bar.setProgress(experience1);
              break;
          case 3:
              double experience2 = Experience.getExperience(p) * 1 / 500;  
              bar.setProgress(experience2);
              break;
          case 4:
              double experience3 = Experience.getExperience(p) * 1 / 800;
              bar.setProgress(experience3);
              break;
          case 5:
              double experience4 = Experience.getExperience(p) * 1 / 1000;  
              bar.setProgress(experience4);
              break;
      }