From the EK career website :
Provident Fund/End of Service Gratuity
On leaving the Company an employee is entitled to an End of Service Gratuity or Provident Scheme payment, whichever is higher. The Provident Scheme is a long-term savings arrangement provided to more senior positions and is designed to help plan for retirement. The company contributes 12% of basic salary. You are required to contribute 5% of your basic salary. End of Service (gratuity) payment is calculated as 21 days basic salary per annum for the first 5 years of service and then 30 days basic salary per annum for each year of service beyond 5 years of service.
Took me 2 minutes... even the taxman is clever enough to find it.