Snakes!!!

Today it won't be any story...I was watching animal planet(as usual)... and came across the top 10 deadliest snakes in africa.... I've seen probably quite a few of these top 10 deadliest snakes... n they claim different sankes at different times.... for some its the black mamba.. for others, the russel's viper... or maybe the king cobra(?india?)..lol.... but nonetheless snakes are extremely fascinating... ok, so how do you state which snake's the deadliest??.. the amount of venom it injects into the victim???... or the amount of venom it stores??.. or by the number of people who die??.. But this show i saw on animal planet had the host giving his own rating based on how aggressive the snake was, how fast it moved, how fast it attacked n the size of its fangs n the amount of venom it injected.... so i think it was pretty fairly done.... but then, you just cannot give the number one , two , three n so on n so forth tags to these mighty reptiles....
how many people die?? how does one find that out? through hospital records??? (funny).... how much venom's needed to kill the victim?? you have the ld 50 test for that.... but is that the only basis???... or how much venom the snake stores???... you'll have different snakes topping the list everytime with each of these parameters....
But one thing's for sure.... I can watch these snake shows any number of times.....:D