How long should the Northwestern Statement be (the "Why NU" essay)?

I'm not sure if the Northwestern Statement should be an essay or a paragraph, they really don't say anything on the NU supplement. The directions read as follows: "The following statements must be typed and submitted on separate sheets of paper. Type your name and birth date on each sheet. Note which item you are addressing at the beginning of each statement." Then it just goes on to describe what the statement should say. There's really nothing about how long it should be. Can anyone who's also applying to Northwestern help me out? Thanks!|||I'd say one to two paragraphs. That's how long mine was.