physics lab results check?

I'm doing a physics lab on light refraction where the data has already been given to me. All I have to do is measure the angles and record my results. Is this accurate, can the refracted angles be different if the incidence angles are all 10 degrees apart?

my results:
angle of incidence = i
angle of refraction = r
there are 9 points

1 - i = 0 deg, r = 0 deg
2. i = 10 deg, r = 7 deg
3- i = 20 deg , r = 14 deg
4 - i = 30 deg, r = 21 deg
5 - i = 40 deg, r = 27 deg
6- i = 50 deg, r = 31 deg
7- i = 60 deg, r = 36 deg
8 - i = 70 deg, r = 40 deg
9 - i = 80 deg, r = 42 deg\
...should this happen..where they get progressively smaller?