Generate quasi-random data for line chart in Java

For prototyping and testing, I want to generate fake sets of data for line charts.

Something like Y-axis values between 0 and 99, with X-axis being points in time (every minute). The idea is to have somewhat realistic-looking data, with some curves going up and down gently. Nothing too fancy, just something better that calling Random which scatters points all over (of course, as it should).

I suppose just generating points along a sine wave, would work – except that I've forgotten all my math schooling. Even better would be something like a sine wave but a little bit more randomized.

Can anyone share some code, or point me in that direction?