NEW DELHI: The Centre on Friday made a strong pitch in Supreme Court for reservation in promotions to the employees of the SC/ST community.When asked by the apex court on the adequacy of reservation, the Centre made its stand very clear and said "in promotions, the SC and ST together must account for 23 of every 100 promotions in a year. Otherwise, the affirmative action would remain an illusion."Attorney general KK Venugopal, appearing for the Centre, said reservations were given to the SC and ST communities to right a wrong they had suffered for more than 1000 years. "Atrocities on them happen even today," he said.A five-judge bench headed by CJI Dipak Misra asked the Centre to prove why the Supreme Court's 2006 ruling asking states to get quantifiable data to prove backwardness before granting reservation is wrong.To this, the Centre told the apex court that there was no need for testing backwardness of SC/ST employees while granting promotion as the top court itself in Indra Sawhney case had said that the test of backwardness does not apply to SCs and STs as they are presumed to be backward.The top court asked the Centre why no state had till date undertaken the exercise of collecting quantifiable data about inadequacy of SC/ST representation in promotion for each cadre of posts.