If the chart is larger than the applet window, then click on the bottom right image to move the window around the chart, or change the text font to a smaller size. Use the options on the right to select which years are included on the chart.
NB On the default Windows Internet Explorer this applet does not work. If you turn on the Java Console (using the Advanced pane on the Internet Options menu) you'll see a message containing 'BufferedImage not found'. You need to installed the Sun Java JRE to get a decent version of Java.