Yoda's unknown species are obviously known for living for hundreds of years, however Yoda dying of natural causes at exactly 900 years old is young for his species.
This is because Grogu by the time of Yoda's death, is 45 years old (4 ABY) and resembles the physical and mental development equivalent of a human toddler. By the New Republic era, he is over 50 and appears to be 3 years old in human years.
With this in mind you could make the argument that 16 plus two third years (16.67) aged of Yoda's species is the equivalent of 1 human year. For example for Grogu to be 6 years old in his species' years, he would need to age 100 years (would reach that age in 41 ABY)
Using this logic of examining Grogu's slow aging, this would mean that Yoda's death at the age of 900 is the equivalent of a human dying at the age of 54.
With Yoda being a very powerful force user and feeling the full suffering of Order 66, dying of natural causes before 70s-80s isn't too much of a surprise. >!Ben Kenobi died at 61 naturally through the force (becoming one with the force is a light-side ability those with not much strength (say less than a few years) left use) and him being able to see and raise Luke from time to time definitely helped him live longer!<