What is the approximate percentage of the world's food crops that are pollinated by insects?

Strange answer. The question is about food crops, but the answer is concerned with all flowering plants. Corn, one of the world's larger food crops is pollinated by the wind.

Wikepeda also Bats are important pollinators of some tropical flowers, visiting to take nectar.[20] Birds, particularly hummingbirds, honeyeaters and sunbirds also accomplish much pollination, especially of deep-throated flowers. Other vertebrates, such as kinkajous, monkeys, lemurs, possums, rodents and lizards[21] have been recorded pollinating some plants.

Player #17763543, Agriculture is almost entirely dependent on angiosperms, which provide virtually all plant-based food, and also provide a significant amount of livestock feed. Of all the families of plants, the Poaceae, or grass family (providing grains), is by far the most important, providing the bulk of all feedstocks (rice, maize, wheat, barley, rye, oats, pearl millet, sugar cane, sorghum). The Fabaceae, or legume family, comes in second place. Also of high importance are the Solanaceae, or nightshade family (potatoes, tomatoes, and peppers, among others); the Cucurbitaceae, or gourd family (including pumpkins and melons); the Brassicaceae, or mustard plant family (including rapeseed and the innumerable varieties of the cabbage species Brassica oleracea); and the Apiaceae, or parsley family. Many of our fruits come from the Rutaceae, or rue family (including oranges, lemons, grapefruits, etc.), and the Rosaceae, or rose family (including apples, pears, cherries, apricots, plums, etc.).[89][90]

Player #17763543, Don't you know that many vegetables and fruits have flowers before they produce the veggie or fruit?

Player #17763543, yes and I just ggled and found that rice is pollinated via gravity... another big crop!

Player ccbkd, wind (for grains, especially) and other animals.