You may or not be entitled to absence relief as described here. Also, see CG65050.
Even if you aren't entitled to absence relief which treats the qualifying period as a period of deemed residence, you can claim letting relief for that period instead. If you forget absence relief and claim letting relief instead I have the following figures:
Total periof of ownership - 189 months
Total owner occupation - 119 months
Total letting period - 59 months
Total vacant period - 11 months
Main residence and last 18 month relief - £117,807 (£162,522/189 x 137 (119 + 18)
Letting relief - £38,696 (£162,522/189 x 45 (59 - 14)
Vacant period gain £6,019 (£162,522/189 x 7) (11 - 4)
The vacant period gain is covered by the annual CGT exemption of £11,100 but you still need to report the disposal as the disposal proceeds were more than £44,400.
I hope this helps but let me know if you have any further questions.