申请PR，写Letter of employment的问题，求解

Employer’s letter stating the date of employment, position held, salary per month for the last 6 months with breakdown into basic, overtime
and allowance per month. The letter, addressed to the Controller of Immigration, should be dated within 1 month from the date of
submission ;

上面这句话有一句话不明白：salary per month for the last 6 months with breakdown into basic, overtime
and allowance per month，  这句话是什么意思？是需要公司一个月一个月细写我过去6个月 每个月的薪水多少吗？ 比如这样：1月-2月 salary :1000, 2月-3月 salary :1000,.....是这样吗，还是不用分6个月细写，直接写 monthly salary :1000？？
还有 我刚跳槽到新公司才三个月，如果是需要这样细写的话也不够6个月呢 该怎么写？？