To achieve the highest marks, both successes and failures must be discussed explicitly and in depth, not just listed, which would limit you to half marks. Remembering two or three figures can make your answer look really good!
Key points you might include and expand on for this question;
Successes: reducing concerns of overpopulation, rate of population growth significantly slowed (c.1.9% 1950, c.0.7%), emancipation of women, enhanced focus on education and family support.
Failures: little emperor syndrome, selective abortions leading to gender imbalance, growing ageing population, human rights issues for women inregards to forced abortions.
Remember that SPaG accounts for 3 marks!