From 1909 to the present day.

Group Medal 1977, Close up

Bronze Cross: first and second successful march.

These are the same design as before, but are now produced in a bright yellow metal.
As old stock was used up first, the move to the new brighter medals may not have taken place in a single year, although some were certainly being awarded from 1987.
 
Left: The cross for the first completed four day march.

Below: The cross, with crown, for two marches.
Below left shows the cross awarded until 2009 with a crown that is an integral part of the cross.
Below right shows the modified design awarded from 2010. The crown is made separately and fixed to the medal prior to award.

Ribbon numbers: From 1977, the numbers attached to the ribbon for a third and fourth march were of a new design, with the number in yellow metal appearing on a glazed green enamel oval shield.

Silver Cross: fifth and sixth successful march.

These are of white metal, rather than the silver used up to 1976.

Left: The cross for five marches awarded from 1977.

Below: The cross, with crown, for six marches.
Below left shows the cross awarded until 2009 with a crown that is an integral part of the cross.
Below right shows the modified design awarded from 2010. The crown is made separately and fixed to the medal prior to award.
 

Ribbon numbers: From 1977, the numbers attached to the ribbon for a seventh, eighth and ninth march were of a new design, with the number in white metal appearing on a glazed blue enamel oval shield.

Gold Cross: tenth and eleventh successful march.

Suspension: All Crosses.

These are dealt with on a separate page:

Awards for 25 or more marches.