A lot of folks seem to be assuming that the village has had a population of 150 for the past 250 years, but it just wouldn't happen that way unless all 150 of them were male elves.
I'll show you why this is so unrealistic.
A population's growth rate is a factor of its birth rate (births plus immigrants) minus its death rate (deaths plus emigrants) in a given year, expressed as a percentage. In the real world this percentage is about 1.5% on average. D&D has two advantages over the real world in terms of growth rate: first, it's modeled after the dark ages where birth control doesn't really exist, education is primative and children are wealth rather than an expense. Second, it allows for all of the conveniences that resulted in exponential growth of humanity following the dark ages. It's not at all outlandish to say that a D&D community has a 8% growth rate. There's no way you could ever fit your described town into that growth rate, so let's say your growth rate is 1.5% instead.
The Rule of 70 says that every 70 years, divided by the percentage growth of your community (70/1.5 or about 50), a community's population doubles (It's a factor of lifespan and fertility, but should be identical for humans in a D&D setting). This means that every 50 years, there were half as many people in that 250 year old town.
50 years ago, there were 80 people in your town.
100 years ago, there were 40 people in your town.
150 years ago, there were 20 people in your town.
200 years ago, there were 10 people in your town.
Remember the figure from above: your birth rate is 1.5% greater than your death rate. That means that there are roughly 148 people buried in your cemetery.
If you wanted to go with a more realistic 8% growth rate, your town could only be around 50 years old to have 150 people, barring some horrible catastrophe. An 8% growth rate left unchecked means that..
250 years ago, there were 2 people in your town and they were very ornery.
241 years ago, there were 4 people in your town.
232 years ago, there were 8 people in your town.
196 years ago, there were 64 people in your town.
160 years ago, there were 512 people in your town.
124 years ago, there were 4,096 people in your town.
88 years ago, there were 32,768 people in your town.
52 years ago, there were 262,144 people in your town.
Today there are approximately 8,388,608 people in your town and countless millions buried in your cemetery.