1. Introduction

2. Data
2.1. Photometry
2.2. Target selection
2.3. Spectroscopy
2.4. Absolute magnitudes and masses
2.5. The dataset

3. The distribution of the rest-frame EW of Lyα

4. The evolution of the fraction of strong Lyα emitters among star-forming galaxies at 2<z<6

5. Lyα escape fraction: driver of the Lyα fraction evolution?

6. Summary, discussion and conclusions