John is right, many helicopters are tested in a dive to around 200 knots, the absolute requirement is to go to at least 1.2 Vh for a military machine (so if Vh is 161, Vdive is 193, in case you're wondering where John Dixson got the 193 from!)
For civil helos it is 1.11 times Vne (or actually, you operators get to fly to 90% of the maximum speed tested).
The S-76 flew a number of world records at 186 to 188 kts in level flight, and the most it has gone in a dive is about 210 knots (John, remember the Kollsman airspeed gauge with the stop at 155 knots, with Pasquarello and Mills flying? There is a great story there......)
The test point at 199 for the 525 tells us they have probably got about 165 max level flight speed, and that test point is fairly normal.