Division with a Filter

Hi! The sample data is above in the OP but I'll put it below too:

IP Address          Month Reported

1.2.3.4                 March 2022

1.2.3.5                 February 2022

1.2.3.6                 November 2021

The desired output is:

IP Address     Month Reported     Percentage

1.2.3.4            March 2022             98%

1.2.3.5            February 2022         93%

1.2.3.6            November 2021      96%

What I have now is: 

Percentage = DIVIDE (COUNT(Table 1[IP Address]), COUNT('Table 2'[IP Address]))

So I'm counting the number of IPs in Table 1 and dividing it by the count of IPs in Table 2. But it's counting all IPs in Table 1 regardless of the month listed in the Month Reported column. Hopefully this is clearer.