循环 stata

求助大佬们， 这样能用循坏语句解决吗？

replace mci_time = r10iwmid- r9iwmid if cf_w10==1 & wave==9
replace mci_time = r11iwmid- r9iwmid if cf_w11==1 & cf_w10!=1 & wave==9
replace mci_time = r12iwmid- r9iwmid if cf_w12==1 & cf_w11!=1 & cf_w10!=1 & wave==9
replace mci_time = r13iwmid- r9iwmid if cf_w13==1 & cf_w12!=1 & cf_w11!=1 & cf_w10!=1 & wave==9


replace mci_time = r11iwmid- r10iwmid if cf_w11==1 & wave==10
replace mci_time = r12iwmid- r10iwmid if cf_w12==1 & cf_w11!=1 & wave==10
replace mci_time = r13iwmid- r10iwmid if cf_w13==1 & cf_w12!=1 & cf_w11!=1 & wave==10


replace mci_time = r12iwmid- r11iwmid if cf_w12==1 & wave==11
replace mci_time = r13iwmid- r11iwmid if cf_w13==1 & cf_w12!=1 & wave==11

replace mci_time = r13iwmid- r12iwmid if cf_w13==1 & wave==12