Conversation so far:
When did the muppets debut?
Produced by the Children's Television Workshop, the program debuted as Sesame Street in 1969.
Were The Muppets popular in the 80s?
The Muppet Show became increasingly popular due to its sketch-variety format, unique form of humor, and prolific roster of guest stars.
How much revenue did The Muppets bring in the 80s?
Disney expressed interest in purchasing the company for $150 million.

Question: When did Disney make that offer?
Self-contained rewrite: When did Disney make the offer to acquire the muppets?