No tomatoes on plants?
Hi- there is a about a two week period between tomato buds opening and flower petals dropping followed by a 40-50 period between flower petals dropping and ripe fruit. If plants are crowded, shaded, and/or over-fertilized with nitrogen you may see lots of blooms and fewer fruits. Side note- pick fruits when they are full size and starting to turn. Ripen fruits on kitchen counter. You will enjoy many more fruit this way. Fruits left to fully ripen on the vine will crack, split, rot, and suffer insect and wildlife injury.
A drop-off in production last August could have been due to many different factors- disease(s) weakening plants over time, using determinate (self-topping) rather than indeterminate cultivars, too much or too little water, etc.