docs: public Long getFileCountAvg() {
          Long fileCountAvg = 0L;
          if (items.size() != 0) {
              for (TableStat item : items) {
                  if (item.getEndTime().equals(item.getStartTime())) {
                      fileCountAvg += item.getFileCount();
                  } else {
                      fileCountAvg += item.getFileCount() * 1000
                                      / (item.getEndTime().getTime() - item.getStartTime().getTime());
                  }
              }
              fileCountAvg = fileCountAvg / items.size();
          }
          return fileCountAvg;
      }