Creating an Reliability Level depending on some values

I want to measure the reliability that I station in a production line has
we evaluate 4 differente categories and those categories has some others sub categories 

what I want to achieve is this 
If the number of events (sum) is < 50 reliability = High
If number of events >= 50 and <75 reliability = Regular

If number of events >=75 and <99 reliability = Medium
If number of events >= 99 and <140 reliability = Bad
If number of events >140 reliability = Non-Reliable

I use this formula but it shows all as "High Reliability" which is incorrect due that some stations have more than 140 events 

Reliability = IF(
Actuadores[Eventos] <50,"High",
IF(AND(Actuadores[Events] >= 50,Actuadores[Events] <75),"Regular",
IF(AND(Actuadores[Events] >= 75, Actuadores[Events] <99),"Medium",
IF(AND(Actuadores[Events] >= 99, Actuadores[Events] <140),"Bad",
IF(Actuadores[Eventos] >140,"Non Reliable")))))


I have to remark that this formula is going to be filtered to a specific station and on the last 2 days of records 
not all of them just Today's and Yesterday's values