Northumberland still showing as live in the las.csv table

## Describe the bug
Northumberland is showing as live in the las.csv data

## How to reproduce
Steps to reproduce the behaviour:
url3 <- "https://raw.githubusercontent.com/dfe-analytical-services/dfe-published-data-qa/main/data/las.csv"
las <- read.csv(url3)

z<- las %>% filter(status =="live", old_la_code!="x") %>% filter(!grepl("/", old_la_code))

#look at z and can see Northumberland as showing live. I think it should be terminated.

I am trying to

## Additional context
I am trying to write some code that can get a list of las based on the date_of_operation and date_of_termination. If there is a better way to do this using the dfeR data, I would be very interested