Hypothesis: as FRF operates for a longer time, they should eventually catch all of the older patients that need surgery, and patient age should get younger over time. Is this true?
Lets graph Age of patient against OperationDate (note, this is for all surgeries in the database):
Looks like the answer is no. Lets confirm by looking at yearly stats:
## Source: local data frame [7 x 5]
##
## OperationYear MedianAge AvgAge StDevAge NumberOfPatients
## 1 2010 1.885 5.148868 7.201965 106
## 2 2011 2.015 4.824274 6.032566 124
## 3 2012 1.215 4.277736 6.979455 106
## 4 2013 3.090 6.288034 6.959233 117
## 5 2014 2.550 6.163566 6.770179 129
## 6 2015 4.510 7.329027 7.050599 113
## 7 NA NA NA NA 80