typing faster

Recently , i try to type letters more faster at Sushida.
now i type 4.3 letters per second.
my friend types 5.7 letters , he is ranked within 100 place at Sushida!!

typing fast is really important , i think.
that skill will be reflected in one's work.
a man who types faster will be able to finish writing reports faster too.
my aim is to type 5 letters per second!!