Some speakers, when pronouncing the numerals in the designation of years of the current first decade of the 21st century, place the conjunction and between the words thousand and nine (for instance). No such conjunction appears when speaking the dates of the 20th century (or earlier). One can hear this trait consistently on the radio in the speech of Garrison Keillor (The Writer’s Almanac), among his other verbal idiosyncrasies (which include––despite his excellent diction and dulcet voice––mispronunciations of common words and entirely contraindicated declamatory habits that do violence to the syntax of the “poems”). British speakers with this trait can also be heard on the BBC World Service.
Why? Is it some sort of superannuated folkway? Could it be the influence of the word thousand (two thousand and nine) instead of twenty (twenty-o-nine)? In any event, there is no need whatsoever for this superfluous syndeton.