Complex sentence: Ever since the late 80's, a plan of renovating the main centre of Vällingby has been tossed around and only in the beginning of the year 2001 was finally accepted by the local political powers.
Split into simpler sentences: Ever since the late 1980's, a plan to renovate the main centre of Vällingby has been tossed around. Only in the beginning of the year 2001 was the plan finally accepted by the local political powers.