The row counting can be done by the dbase as in
SELECT count(%your_field) as c_field FROM %your_table% ORDER BY c_field DESC;
will return a descending list of instance counts
the iterate
while ($row=mysql_fetch_array($sql_result)) // where $sql_result is the result of the previous SQL
{
for ($counter=0;$counter<$row["c_field"];$counter++)
{
echo "x";
}
echo "<br>";
}
This code outputs an x for each count,
echo "x" can be replaced with a more graphical output procedure like a small icon or a drawing in an image.
Saludos
Gerardo