The salary formula features fixed and variable pay components which are linked to individual performance and national outcomes, i.e. Annual Salary = Fixed (13 months) + Annual Variable Component (typically 1 month) + Individual Performance Bonus (3 months for good performance) + National Bonus (3 months if targets are met) = 20 months. The salaries of the appointment holders are performance-linked, to ensure that the leaders are accountable for their roles and responsibilities. The salaries are also linked to the socio-economic outcomes of Singaporeans. As of 2012, when the Ministerial salaries were last adjusted, the reference monthly salary for a MR4 Minister (mid-point of the range) was S$55,000. This works out to an annual salary of $1,100,000. The fixed salary is $715,000, and the rest is variable. A Minister may start at the lower end of the MR4 range with a monthly salary of $46,750. This works out to an annual salary of $935,000, of which $607,750 is fixed and the rest is variable.