Metallicity distribution. Top: all stars (logarithmic scale) in SWEET-Cat, divided in three groups: blue (the largest distribution) are all stars available in SWEET-Cat; green (the middle distribution) are the stars with homogeneity flag 1, i.e. analysed using the method described in this paper; and red (the smallest distribution) are all new stars added from this paper. Bottom: 12 V magnitude cut to exclude stars which are currently unavailable spectroscopically.