While this Bistro type set is based on the Art Deco style popular from the 1930's until World War Two ( 1939), it's unlikely it predates the 1980's. Sets like this have fairly high retail values when first sold, but take drastic drops in value once they leave the store. Values for these sets in the resale/secondary market today depends now a great deal on their Designer, condition and quality of construction.
Unmarked Bistro sets like this one that were made in large numbers have modest values in the secondary market compared to examples by well known Designers. Most used sets tend to sell through restaurant supply Wholesalers and Liquidators, as restaurants have very high failure rates. Furniture in this style is currently very popular, with sets like this one now often selling at auction in the $800.00- $1200.00 range.