Trying to calculate confidence intervals

#1
Hi everyone. The numbers below are the annual maintenance costs of a program I am working on. I'd like to use the data set to estimate future costs at different confidence intervals (e.g. 80%). Can you help me with what distribution would be best and how to produce a CDF that I can graph different confidence levels on using Excel?

1,966,763
1,867,331
2,059,427
1,856,963
1,847,963

Thanks in advance!
CostGeek