I had lived in Asia for 20 years. And in that time I met many Asian missionaries who have 1 to 3 supporters. Surprisingly these one to 3 supporters cover their basic needs. But we should ask the question, "How many supporters should a missionary have?"
One time one of our supporters came to the Philippines and I asked him to share to our staff. He is a business man and he gave us a unique perspective.
He told us that if you are running a business and you had it is growing to the point where you need to expand and need a loan one of the first questions the bank will ask is about your customer base. He said that if 25% of your business is from one customer the bank will not give you a loan because you are, "high risk."
This can also be applied to our support base. If 25% of our support base is from one supporter our ministry is at high risk.
If you have 4 supporters giving 25% equally and you lose one supporter for whatever reason you take a major hit. It is better to have 10 supporters giving 10% each then 2 giving 50% each (I understand it never works out that way).
Personally I have talked to missionaries who only had one supporter and lost their supporter. They started talking about leaving the mission field because of lack of funds.
So what does this mean?
Even if you are fully supported with 3 or 4 supporters, you need to expand your support base. Praise God if you are one of those who fully supported by only a few. But take that has God's grace and a time that you can spread out your support base. Keep building your contact list and communicate with potential supporters. I know that after 20 years as a missionary your support base will change. It always does. Some people will stop supporting and then others will join in. But if you are not working on your support base you cannot make it the long hall.
Most of us when reading the book of Philippians don't think about what it was. It is Paul writing a letter to his supporters. He was discipling and thanking them for their support. As missionaries let us keep lines of communication to those who support us.
If you need some help with raising your support please go to https://www.unmuzzledox.com/ , sign up for their blog, and read more tips on how to raise your support.