One of the ironies is that test pilots have trouble getting life insurance, yet its extremely rare that a test pilot for a major aerospace company has a serious accident. I can think of two crashes involving test pilots in recent years that resulted in fatalities (or serious injuries)
Virgin also lost Spaceship Two with one fatality in 2014 and Swearingen lost an SJ30 prototype in 2003. (The second is arguably is or is not in recent years.)
Military and E-AB (Experimental-Amateur Built) aircraft also have a higher than normal flight ops fatality rate, which speaks to the test pilot insurance rate, not directly to "routine testing of new civilian aircraft" level of safety.
[0] https://aviation-safety.net/database/record.php?id=20110402-...
[1] https://aviation-safety.net/wikibase/wiki.php?id=188544