I don't think that it's fair to compare CCTs (hospital to hospital or hospital to sub acute [vent dependent patients]) with SNF to doctors office or SNF to dialysis clinic.
That said, I find it rather odd for an ambulance company to have absolutely zero emergency calls [even if it's SNF->ER, non-911 "emergency" calls]. Sure, if you're looking for trauma and car crashes, then sure, you won't run any "emergency" calls. Sure, most of these type of "emergency" calls are not really emergent, but you will run into either weird [so, Mr. Jones, your arm has been cold, numb, and pale since you woke up this morning and you had surgery last week?] or truly emergent [Hey, Phil, mind trying to get a BP for me just to make sure? Yea, I was getting something around 60/30 too].