请问谁能解释一下，F1 的排期怎么晚过 F2A? 排期连接见内。多谢

https://travel.state.gov/content/visas/en/law-and-policy/bulletin/2018/visa-bulletin-for-october-2017.html

 

Family- Sponsored	All Chargeability  Areas Except Those Listed	CHINA-mainland  born	INDIA	MEXICO	PHILIPPINES
F1	22DEC10	22DEC10	22DEC10	01MAR96	01JAN07
F2A	22OCT15	22OCT15	22OCT15	15OCT15	22OCT15
F2B	08NOV10	08NOV10	08NOV10	15JUL96	01JAN07
F3	22JUL05	22JUL05	22JUL05	22APR95	22FEB95
F4	08MAY04	08MAY04	01OCT03	01OCT97	01JUN94