a1=Import["http://islands.unep.ch/Tiarea.htm"];

a2=StringSplit[a1];

a3=Select[a2, StringMatchQ[#,NumberString]&];

a4=ToExpression[a3];
a5=Union[10*a4]//Round;

a6=IntegerString[a5];

a7=Table[ToExpression[StringTake[a6[[i]],1]],{i,Length[a6]}];

Histogram[a7]