[sonjay]

It says the death rate has been reduced by 60%

Actually, it says the death rate is 60 percent. There's a comma after 60 percent -- so it is saying that the death rate is 60%, (which is) lower than than the 90 percent rate in previous outbreaks.

Notice the comma:
"the death rate of the outbreak that began in March is 60 percent, lower than the 90 percent rate in some previous outbreaks"

[Bruce Kurtz]

Missed the comma