SQLite: How to reduce byte size of integer values?

I have a SQLite table (without row ID, but that's probably irrelevant, and without any indexes) where my rows contain the following data:

• 2 real values, one of which is the primary key


• 3 integers < 100


• 1 more field for integers, but currently always null

According to http://ift.tt/1aUsJJH, integer values can take 1, 2, 3, 4, 6 or 8 bytes according to their magnitude. Therefore I'd expect each row in my table to take up about 20 bytes. In reality, sqlite3_analyzer gives me for the table

Average payload per entry......................... 25.65     
Maximum payload per entry......................... 26

which is somewhere in between the minimum value of 20 and the maximum of 32 (if all integers were stored with 4 bytes). Is it possible to give the DB a "hint" to use even smaller integer types wherever possible? Or how else can the discrepancy be explained? (I don't think it's indexes because there are none for this table.)

Similarly, on a previous table I had 2 real values + 2 small integers and each entry occupied slightly more than 24 bytes (which is also more than I would have expected).

Also, there is no way to store floats in single precision with SQLite right?