Tier2 (General) Extension Salary Confusion

Dear Gurus,
I am due to apply for my Tier2(g) extension on Aug-2017. I have a confusion regarding required salary for experienced worker.

My SOC code is 2135 and required salary by UKVI is £34700 per year for weekly 39 Hours.
But in reality i do 40 hours per week. So how much i need to show as yearly salary?

Currently i am getting salary £34200 per year.

I did the calculation as follows:
UKVI requirement: £34700 /(39 hours x 52 Weeks) = £17.11 per hour
I am now getting: £34200 /(40 hours x 52 Weeks) = £16.44 per hour

My questions are

1. Am i getting enough to quality the extension?
2. The way i did the calculation is correct?

Thanks in advance.

34700/39*40 = 35589.7435897

Thanks a ton