When there are a lot of seats to be filled, as in a legislature, counting ballots under PAV may not be feasible, so sequential variants have been proposed, such as Sequential proportional approval voting (SPAV). This method is similar to reweighted range voting in that several winners are elected using a multi-round counting procedure in which ballots supporting already elected candidates are given reduced weights. Under SPAV, however, a voter can only choose to approve or disapprove of each candidate, as in approval voting. SPAV was used briefly in Sweden during the early 1900s.