What are the five fastest horses in Kentucky Derby history?

The five fastest horses in Kentucky Derby history are as follows :

1. Secretariat [March 30, 1970 - October 4, 1989], 1:59-2/5 in 1973;

2. Monarchos [foaled 1998], 1:59.97 in 2001;

3. Northern Dancer [May 27, 1961 - November 16, 1990], 2:00:00 in 1964;

4. Spend a Buck [1982 - November 24, 2002], 2:00-1/5 in 1985;

5. Decidedly [1959 - ?], 2:00-2/5 in 1962.