It really depends on the individual circumstances. There is no limit in terms of the number of hours. There is a tier in terms of the limit, in terms of how many dollars can be contributed towards that client for that particular service, but no actual limit in terms for the number of hours. So in some cases you can get a greater number of hours at a lesser per-hour cost or charge and in other circumstances less, depending on the type of services you receive.
On May 11th, 2009. See this statement in context.