What percentage is listed in column r1b1c (r-v88) for the 4.5% total percentage?
create table table_21481509_4 (r1b1c__r_v88_ varchar, total_percentage varchar, PRIMARY KEY (r1b1c__r_v88_))
select r1b1c__r_v88_ from table_21481509_4 where total_percentage = "4.5%"