In my case I was married for 9 years to a guy who worked at the same company for 10 years. We had our son after 2 years of marriage. Our daughter after 6 years. (She passed away).
After our divorce he was court ordered to pay 90 dollars a month for our son. (He was working a minimum wage job by that time.) He only pays maybe once a year. He hasn't worked in about a year. I never imagined he would be one of 'those' dads.
Of course I have never relied on CS as it wouldn't make much of a difference anyway.