Question for those working for large corporations

[Questioner]

Does anyone else work for a company where your "utilization" (billable hours worked) has to equal or exceed greater than 100% so that when you take vacation it doesn't negatively impact your "utilization"? I'm also a "salaried" employee meaning that I don't get paid any extra if I work more than 40 hours a week (50 is fairly average).

For example, if there are 52 weeks in a year, and a person gets two weeks vacation, if they only worked 40 hours per week for the other 50 weeks of the year they would be negatively impacted by taking vacation.... but if they work in another 80 hours during the remaining 50 weeks in the year, then their utilization would be back to 100%. These statistics are also impacted negatively by holidays, training classes, having more than two weeks vacation in a year, etc. If a person gets 4 weeks vacation in a year, he/she has to work an extra 160 hours during the remaining 48 weeks in the year to maintain 100% utilization, assuming that all 40 of the hours each week are considered "billable" hours and charged to a client.

I'm just curious as to how prevalent this is in today's job market. I've accepted it as something that I can't do anything about (especially given the size of the company I work for) and have factored in the "you're just lucky to have a job" thing.