Einstein's Riddle

I came across a riddle that supposedly Albert Einstein wrote early in the last century and claimed that 98% of the world population would not be able to solve it.

It doesn't use word play, just logic. If you believe you have the answer, post your answer in BBCode tagged to size 2 so it won't spoil it for others.
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1. In a street there are five houses, painted five different colours.
2. In each house lives a person of a different nationality.
3. Each homeowner drinks a different kind of beverage, smoke different brands of cigarettes and keeps a different pet.
4. The Brit lives in a red house.
5. The Swede keeps dogs as pets.
6. The Dane drinks tea.
7. The green house is next to, and on the left of the white house.
8. The owner of the green house drinks coffee.
9. The person who smokes Pall Mall rears birds.
10. The owner of the yellow house smokes Dunhill.
11. The man living in the center house drinks milk.
12. The Norwegian lives in the first house.
13. The man who smokes Blends lives next to the one who keeps cats.
14. The man who keeps horses lives next to the man who smokes Dunhill.
15. The man who smokes Blue Master drinks beer.
16. The German smokes Prince.
17. The Norwegian lives next to the blue house.
18. The man who smokes Blends has a neighbor who drinks water.

Who owns the fish?