MYSQl Data not displaying numbers in order

Hello,

I have the following code to get data from mysql.

SELECT COUNT(*),pickup FROM journeys WHERE pickup_type='postcode' GROUP BY pickup HAVING COUNT(*)>=1

The result is like this;

E1

E10

E11

E12

E13

E2

E3

E4

.......

I need to display the data starting from E1 ...... to ....E13 (or whatever the last entry is).

Could anyone help?

Regards