public static int calculatePagePositionPercent(long currentPageNumber, long pageAmount) {
    int progressValue;
    if (currentPageNumber == 0) {
      progressValue = 0;
    }
    else if (currentPageNumber == pageAmount - 1) {
      progressValue = 100;
    }
    else {
      progressValue = (int)(1 + 99 * (currentPageNumber - 1) / (pageAmount - 1 - 1)); // magic formula
    }
    return progressValue;
  }
public static int calculatePagePositionPercent(long currentPageNumber, long pageAmount)