Brainstorm: (untested)
you might be able to get somewhere using the SUM and IF statement:
SELECT
sum(
if (tranasactions.stonage_ID>48
and transactions.year>2000,1,0)
)
FROM bla
GROUP BY otherbla;
you can put several SUM(IF())'s in the select to get all results at the same time.
Check the MySQL manual for more info on IF()