Yes that is very low. But where they 120 all across the board? I'm assuming so because that's what you said so its time for a rebuild.
Normal Pressure Range: 130.5psi - 203psi
Wear Limit: 108.75psi (If any of your cylinders are even 10psi near this range, start listing that car for sale on eBay ...or start saving for that rebuild you've been talking about.)
Maximum Difference Between Cylinders: 43.5psi
Cliff's Notes: What you want to see are CONSISTENT numbers where the difference in pressure between cylinder are within a few psi from each other. A healthy 1.8T engine should typically be within around 170-180psi (testing conditions will vary). If your results show lower (130-140psi) across all cylinders, do not panic. Though your engine may not be working like "new", your numbers are consistent and the engine is simple "getting tired" However, seeing 140psi is very unlikely. There are engines out there with well over 150k that still test 160psi+. However, if you have one (or two) cylinders that test especially lower than the other cylinders, this is something that you may need to address.
If you come across one cylinder that is lower than others, you can start by trying to narrow down the causes. The first and easiest test is to see if the leak is coming through blowby (worn piston rings). To see if your rings are worn, simply pour about 1/2 to 1 teaspoon of motor oil into the spark plug hole of that cylinder in question. The oil will help a worn ring seal itself. Then retest that cylinder. If compression numbers now read higher, your piston ring is worn. If results are still the same, then your rings are fine, and the leak is coming from the valve train and/or head gasket (leak-down test will confirm).
Some Typical Results:
165, 160, 170, 165 <~ Healthy Engine
180, 145, 175, 170 <~ Cylinder #2 is questionable, but engine should still be okay
130, 140, 125, 130 <~ Engine could be old and tired, but still considered healthy
180, 180, 175, 180 <~ A Healthy and Strong Engine
170, 165, 180, 105 <~ Something is definitely wrong with Cylinder #4, perform a leak-down immediately
170, 120, 120, 170 <~ Cylinders #2 and #3 are lower than normal, which could be caused by a faulty head gasket. Perform leak-down.
95, 105, 100, 100 <~ Your engine is throwing in the white towel, time for a rebuild.
Cylinder compression tests should be done occasionally as a general health assessment for your car. It's good practice to perform a test every few months, and record the test results through the life of your car.