What is Compass Rose on Navigational charts ?

Note :

Sometimes the annual change in variation is noted as east or west, rather than increasing or decreasing. If the annual change has the same name (east or west) as the variation, variation is increasing. If the names are opposite, variation is decreasing.

For example: If your compass rose says 20°20’W (20’E), this indicates a decrease of 20 minutes a year because the names, W and E, are opposite. If it says 20°20’W  (20’W), that would indicate an increase by 20 minutes a year because the names are the same.