This scale measures the toxicity of the venom, not the deadliness of the snake. As most Australian elapids inject relatively small amounts of venom per bite, this does not really reflect their dangerousness compared to other snakes.
An Eastern Brown, for example, injects about 5 mg per bite
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=6857711&dopt=AbstractPlus
while a Black Mamba injects about 100 mg.
http://www.sheppardsoftware.com/content/animals/animals/reptiles/blackmamba.htm
Here is a list that takes this into account:
1) Fierce Snake or Inland Taipan (Oxyuranus microlepidotus ), Australia. This has the most toxic venom of any snake. Maximum yield recorded (for one bite) is 110mg. That would probably be enough to kill over 100 people or 250,000 mice.
2) Australian Brown Snake (Pseudonaja textilis ), Australia. One 1/14,000 of an ounce of this venom is enough to kill a person.
3) Malayan Krait (Bungarus candidus ), Southeast Asia and Indonesia. 50% of the bites from this snake are fatal even with the use of antivenin treatment.
4) Taipan (Oxyuranus scutellatus ), Australia. The venom delivered in a single Taipan bite is enough to kill up to 12,000 guinea pigs.
5) Tiger Snake (Notechis scutatus ), Australia. The Tiger snake is a very aggressive snake that kills more people in Australia that any other snake on that continent.
6) Beaked Sea Snake (Enhydrina schistosa ), South Asian waters Arabian Sea to Coral Sea.
7) Saw Scaled Viper (Echis carinatus ), Middle East Asia. Saw Scaled Vipers kill more people in Africa than all the other venomous African snakes combined. Its venom is 5 times more toxic than that of the cobra.
8) Coral Snake (Micrurus fulvius ), North America. Coral Snakes have a very potent venom but many are too small to deliver enough venom to kill a human. It is elapid (relative of the cobras and mambas).
9) Boomslang (Dispholidus typus ), Africa. The Boomslang is the most seriously venomous rear-fanged snake in the world. They have very long fangs and can open their mouths a full 180 degrees to bite.
10) Death Adder (Acanthophis antarcticus ), Australia and New Guinea. A dosage of 10mg of Death Adder venom is enough to kill a human. A good sized Death Adder can deliver up to 180mg in a single bite.
(from
http://www.chm.bris.ac.uk/webprojects2003/stoneley/strength.htm)