Add migration for monthly stats

		);

		$dbh->commit;

	},

	# v3 -> v4

	sub {

		$dbh->begin_work;

		$dbh->do(

			qq{

			update schema_version set version = 4;

		}

		);

		$dbh->do(

			qq{

			create table monthly_stats (

				user_id integer not null,

				year int not null,

				month int not null,

				km_route int not null,

				km_beeline int not null,

				min_travel_sched int not null,

				min_travel_real int not null,

				min_change_sched int not null,

				min_change_real int not null,

				num_cancelled int not null,

				num_trains int not null,

				num_journeys int not null,

				primary key (user_id, year, month)

			);

		}

		);

		$dbh->commit;

	},

);

my $schema_version = get_schema_version();