why is it that even though our incomes and deductions have remain nearly the same for the past two years there is well over $800.00 difference in our refund?

The amounts of your withholdings may have changed.   You would need to print them out or view them side by side and go through each line to see where the differences are coming from.   The article below has some other possibilities to look for when you compare the returns.

Why is my refund lower than last year?