I got a class that I use as a table. This class got an array of 16 row classes. These row classes all have 6 double variables. The values of these rows are set once and never change.

Would it be a good practice to make this table a singleton? The advantage is that it cost less memory, but the table will be called from multiple threads so I have to synchronize my code which way cause a bit slower application. However lookups in this table are probably a very small portion of the total code that is executed.

EDIT: This is my code, are there better ways to do this or is this a good practice? Removed synchronized keyword according to recommendations in this question.

final class HalfTimeTable {
    private HalfTimeRow[] table = new HalfTimeRow[16];
    private static final HalfTimeTable instance = new HalfTimeTable();

    private HalfTimeTable() {
        if (instance != null) {
            throw new IllegalStateException("Already instantiated");
        }
        table[0] = new HalfTimeRow(4.0, 1.2599, 0.5050, 1.5, 1.7435, 0.1911);
        table[1] = new HalfTimeRow(8.0, 1.0000, 0.6514, 3.0, 1.3838, 0.4295);
        //etc
    }

    @Override
    @Deprecated
    public Object clone() throws CloneNotSupportedException {
        throw new CloneNotSupportedException(); 
    }

    public static HalfTimeTable getInstance() {
        return instance;
    }

    public HalfTimeRow getRow(int rownumber) {
        return table[rownumber];
    }
}