The current number of records can be found in the status line below. This number of documents is not completely loaded (this would be too time consuming). Rather, a few dozen records are loaded first.
To retrieve more records, you can use the mouse or a touchscreen display to scroll all the way down the scroll bar on the right. When you do this, an hourglass appears briefly and the slider in the scroll bar becomes smaller. In a nutshell, more datasets have been loaded and can now be examined directly.