Change in parents income

My parents combined income for my student loan purposes in 2018/2019 was 59,000.00 per annum.It has now dropped to 49000.00 per annum as my father now earns 37000 per annum. since last year and will drop further to 37,000.00 as my mum is taking a masters degree in social work the next academic session. How can I reflect this before I obtain my student loan as it appears the figure on which this loan is based is much higher than current income figures.