If someone was on low income or on a fixed income, would you expect them to tithe 10% of it to a church?

I know not all Christians do that (give 10% of their income literately) but I know people personally who are evangelicals who stick by that even though we are in a tough economy. But I was thinking would a Christian expect someone on disability, SSI, welfare, or just a minimum wage job to literately give 10% of their monthly or yearly income to a church/Jesus?