How to do arithmetic in Spring properties?

<bean id="simpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
        <property name="jobDetail" ref="Job1" />
        <property name="repeatInterval" value="1" />
    </bean>

I want to load value from a property file (value = "${jobs.per.second}"), which will be manipulated.

For example: jobs.properties file will have: jobs.per.second = 500

I want to use arithmetic operations (invert it and multiply it by 1000) (1/500 * 1000 = 2) and substitute value = 2 instead of 1.

How do I go about it? Is there any way to enable arithmetic operations in xml?

EDIT: I am using Spring 3.