My parents wont let me stay out late?

I'm turning fifteen in three months and I'm the oldest in mj friendship group and all of them are allowed out until ten o clock at the least, I'm not a radji I'm always Honest to my parents about who I'm with and what I'm doing and where I am yet they make me come in for eight all the time, yet I have to get two buses and that alone takes an hour because if I'm late they'll bollock me yet I never come home late or drunk or anything and I have really good grades at school, my Mam always thinks I'm up to no good when I'm genuinally not, they interrogate me on whether I've been drinking and last time I came in I sprayed some deodorant and they thought I had been smoking and was trying to cover it up :l now they give me no privacy and have even started stalking my Facebook thru an anonymous person which I don't know, are they being so unreasonable? And they take a complete radjj if I have even been in the vicinity of boys :l what time would you say was a good curfew?