Sebco.org is around 15 years old, which shows that it is a very established website. Older websites are considered to be more trustworthy and usually we advice to use caution with websites which are younger than 1 year.
A website with a domain expiration time of less than 1 year is considered to be less reliable.
The time can be extended by the website owner in the future, and it doesn't mean that the website will vanish after 3 years.
Still, the value indicates how serious the website owners are with regard to their website, and you should use caution with websites which have domain expiration period of less than 1 year.
Alexa rank is a measure of the popularity of the website, a lower alexa rank indicates more visitors, and hence more reliability. Sebco.org is ranked 24,313,258 most visited website on the Internet, out of millions of active websites, which is not so good.