给定一段话，请生成一系列问题来测试阅读者对内容的理解。


很多人认为10,000步是每天保持健康的步数目标。但是，根据一项研究，这个数字可能还不够。实际上，每天走12,000步可以更好地保护心血管健康。研究人员分析了86名平均年龄为66岁的女性的步数，并发现那些每天走12,000步的女性，比走10,000步女性的心血管风险低了21％。
1. What do many people believe is the daily step goal for maintaining good health? 
2. According to a study, how many daily steps may be better for cardiovascular health than the commonly believed target of 10,000 steps? 
3. What did researchers analyze to reach the conclusion that 12,000 daily steps may be better for cardiovascular health? 
4. What was the age and gender of the subjects analyzed in the study? 
5. What was the difference in cardiovascular risk between women who walked 12,000 steps daily and those who walked 10,000 steps daily?