How come my boobs and the back of my legs don't tan?

iv been going on sunbeds for years, are you going on flat beds or stands?? i was having the same problem with areas of my body that werent tanning i looked all odd and multi coloured lol , try and use flats and stands, mix them up coz the bits the flat beds miss out the stands get and vice versa so use flats and stands and your colour will even out, on your legs its something to do with the circulation and you dont tan in places so ui have to use both to be even :) and also make sure your tanning shop changes their tubes often enough