According to The Report of the WHO-China Joint Mission published by WHO and a paper by the Chinese CCDC, which is based on 72,314 cases, the probability of dying if infected by the virus increases with age. This is the table:
As You can see, older people are at greatest risk.
Although this sounds scary and age is the major factor, we can't control it. We can't do anything about getting older so we'd like to focus on other susceptibility factors that are in our control.
So what are other susceptibility factors?
Weak immune system