Is Japanese text more commonly written vertically or horizontally?

All extant historical documents in Japan are written vertically.
Long ago, Japanese was only written vertically.
However, with the introduction of Western writing materials and the need to accommodate the alphabet, arabic numerals, and mathematical formulas, the vertical style seemed ill-suited.
Fortunately, since each individual kanji and kana has its own mean in and function, they could be arranged vertically or horizontally without losing their meaning, Science-related text, which required the use of numbers and foreign words, gradually came to be written in the horizontal stvle.
Todav, most school textbooks - with the exception of subjects such as Japanese or classical literature - are set in horizontal text.
Most general books sold in stores are set in vertical text.
However, as young people today find no difficulty reading or writing Japanese in horizontal lines, this style will become increasing common in the future.