So, one table describing agents, with columns for agent, date and projected cashflow will store all your data...
(index agent & date for performance)
eg: for a summary for all agents for the last 12 months:
select agent, sum(cashflow)
from table
where date >= now() - interval '1 year'
group by agent
order by agent;
or a cashflow aggregate summary for the latest month
select sum(cashflow), avg(cashflow), min(cashflow), max(cashflow)
from table
where date = (select max(date) from table);
or get the agent with highest projected cashflow for the latest month
select agent
from table
where date = (select max(date) from table)
and cashflow=(select max(cashflow) from table
where date = (select max(date) from table));