Replace the question mark with a number

"What do you call Santa’s most impolite reindeer?"
"Rude-olph."

"What street in France do reindeer live on?"
"Rue Dolph."

"How much does it cost Santa to park his sleigh and reindeer?"
"Nothing, it’s on the house!"

"What did Mrs. Claus say to Santa when she looked up in the sky?"
"Looks like rein, deer!"

"Why doesn’t Santa use reindeer milk in his coffee?"
"He’s on a non-deery diet."

"What kind of money do reindeer use?"
"Bucks!"