If a CDS is x%, why does this mean $(1 - x)\%$ probability of default? At 11:52, Tim Bennett says:


  Well let's have a look at
  11:52
  some prices. Currently the cost of
  11:57
  insuring Greek debt is in excess of
  12:02
  $\color{green}{2,000}$ basis points. Another way of
  12:07
  looking at that is that you are paying as a
  12:09
  premium annually $1/5$th of the value
  12:12
  of the debt in question. So another way
  12:16
  of looking at that is: the market is
  12:19
  effectively giving the chance of Greeks
  12:20
  going bust within five years over $\color{red}{80\%}$
  probability.


Doesn't the cost a Credit Default Swap (CDS) for Greek debt is $\color{green}{20\% (= 2000}$ bp), entail that the chance of default by Greece is also 20%? Why  $\color{red}{80\%}$?
Note that the 20% annual premium would imply a 20% annual default probability. Tim Bennett is then talking about the probability of default within five years.

He might have thought that
$$
1 - Prob(\text{no default for five years running}) = 1 - (1 - 0.2)^5 &gt; 0.8 
$$
but this is not true as 
$$
1 - (1 - 0.2)^5 \approx 0.67
$$