How many siblings (brothers and sisters) does Ron Weasley have in 'Harry Potter'?

Ron Weasley has six siblings: Bill, Charlie, Percy, Fred, George and Ginny.

Bill is the oldest and works for the wizarding bank Grongotts in Egypt and then in England.
Charlie works with Dragons in Romania.
Percy attends Hogwarts in books 1 through three then works for the Ministry.
Fred and George attend Hogwarts through to book 5 when they leave to open a joke shop together.
Ron of course is next.
Ginny attends Hogwarts from book two and later marries Harry to live happily ever after!

Auror Ronald Bilius[30] "Ron" Weasley (b. 1 March 1980) was an English pure-blood[2][3] wizard, the sixth and youngest son of Arthur and Molly Weasley (née Prewett). He was also the younger brother of Bill, Charlie, Percy, Fred, George, and the elder brother of Ginny. Ron and his siblings lived at The Burrow, on the outskirts of Ottery St Catchpole, Devon.

https://harrypotter.fandom.com/wiki/Ronald_Weasley

Who is Bill? I thought Ron had only 5 siblings, Charlie, Ginny, Fred, George and Percy.

Bill is the one working for Gringotts Bank.

heres the weasley family.
muriel prewett
molly prewett
arthur weasley
bilius weasley
william arthur bill weasley
ronald bilius weasley
percy ignatus weasley
ginerva molly weasley
fred weasley
george weasley
charlie weasley
fleur delacour
victoria weasley
harry james potter
lily luna potter
james sirius potter
albus severus potter
hermione jean granger
hugo weasley
rose weasley
angelina johnson
fred jr. weasley