Every section above describes the violence each season contains. It's quite evident that violence increases as the series progresses, and gets more graphic, bloody and intense. Some seasons have a body horror aproach, and some have more light violent content. All seasons include deaths: some by shooting, stabbings, choking, impalings, heart ripping, and more disturbing ways (depending on the season). There's a viable amount of blood and some gore as well.
Season One featured a "bad guy of the week" formula in which Clark would fight a 'meteor freak' in every episode. Most of these episodes feature moderate fantasy violence with little blood/gore.
The show gets darker and more graphic from Season 2 onwards. Some aftermaths of crimes are gory. A meteor freak gets impaled by a large piece of sharp metal from a wreckage during a fight with Clark. We see the structure sticking out from her back covered with her blood.
Season 4's episode "Forever" features some graphic horror violence. A man holds a severed head of a young woman before dropping it to the ground and it breaks to bloody pieces.
One episode in Season 5 has Brainiac suddenly stab a man with his hand that has transformed into a blade (we see the blade protrude from his back). In the episode "Mortal", a character vomits a lot of thick blood after getting shot.
Seasons 6 to 10 on the whole features more graphic violence than Seasons 1 to 5.
Season 6 features a scene where a man is graphically impaled by a falling sharp object and we see a lot of blood spill on the ground after that. A woman gets stabbed in the episode "Phantom" and we see her graphically pulling out the knife from her stomach with lots of blood pouring out. In the season premiere, Zod stabs Lana's hand to a wall brutally. We see her struggling to take it out as she screams in pain. Very disturbing. A creature tears out the spine of a man (seen from a distance) A man possessed by an alien being punches through an alien man's stomach and we see gory detail.
Season 7's episode "Bizarro" contains a scene where Bizarro is shown to be impaled after being punched hard into a telephone wire pole by Clark. We then see him graphically pull out the pole from his body. Another episode has Bizarro punch a hole through a black man and we see blood pouring from his wound. In "Apocalypse", a man shoots another man in the stomach and he touches the bloody wound and he gets shot again and we see blood spurt from his shoulder.
Season 8 features one gory scene in a dream sequence where a character is seen torn in half and hanging on a wall briefly. Clark is shot repeatedly with arrows by Green Arrow and we see a lot of blood. A creature slashes a man and blood spurts. A woman impales a man with a metal pole and we see him drop to the ground with lots of blood pooling around his body. In the episode "Doomsday", two man stab each other brutally to death.
Season 9 is the darkest season. Daggers being extracted graphically from open wounds are present most notably in the episode "Pandora". Graphic horror violence is present in the episode "Rabid".
Season 10 has graphic violent sequences such as in Episode 19 where a large amount of blood spurting is seen and close-ups of a sword piercing through a mans back with blood dripping from it is shown.
Overall, every season contains some moments of strong violence. Some episodes feature horror themes in which more bloody violence is depicted.