哪位大神知道这种重复的变量相减怎么用循环语句写出来呀

gen num20200101=Cases20200101
replace num20200102=Cases20200102-Cases20200101
replace num20200103=Cases20200103-Cases20200102
replace num20200104=Cases20200104-Cases20200103
replace num20200105=Cases20200105-Cases20200104
replace num20200106=Cases20200106-Cases20200105