Backup and Restore Statistics by Using dbms_stats

To create table to backup statistics
execute dbms_stats.create_stat_table(ownname= 'scott', stattab= 'backup_stats');

To export statistics into table 
exec dbms_stats.export_table_stats(ownname=>'scott', tabname=>'test', statown=>'scott', stattab=>'backup_stats', cascade=>true);

To import statistics from statistics table
exec dbms_stats.import_table_stats(ownname=>'scott', tabname=>'test1', statown=>'scott', stattab=>'backup_stats', cascade=>true);

To drop statistics table  
execute dbms_stats.drop_stat_table(ownname= 'scott', stattab= 'backup_stats');