explain this 
import csv

# Define the path to the CSV file
csv_file = 'C:/NAME_1/10lottodb-5/28.csv'

# Initialize the statistics dictionary
statistics = {}

# Read the CSV file and extract the numbers
with open(csv_file, 'r') as file:
    reader = csv.reader(file)
    numbers = [int(row[0]) for row in reader]

# Divide the numbers into groups of 20 using list comprehension
groups = [numbers[i:i+20] for i in range(0, len(numbers), 20)]

# Iterate over each group (except the last one)
for i in range(len(groups) - 1):
    current_group = groups[i]
    next_group = groups[i+1]

    # Iterate over each number in the current group
    for number in current_group:
        # Update the total_occurrences count for the current number
        if number in statistics:
            statistics[number]['total_occurrences'] += 1
        else:
            statistics[number] = {'total_occurrences': 1}

        # Find the most frequent number in the next group when the current number is present
        occurrences = [next_num for next_num in next_group if next_num != number]
        if occurrences:
            most_frequent = max(set(occurrences), key=occurrences.count)
            statistics[number]['most_frequent_next'] = most_frequent

# Print the final statistics for each number from 1 to 90
for number in range(1, 91):
    if number in statistics:
        print(f"Statistics for number {number}:")
        print(f"Total occurrences: {statistics[number]['total_occurrences']}")
        if 'most_frequent_next' in statistics[number]:
            most_frequent = statistics[number]['most_frequent_next']
            occurrence_count = occurrences.count(most_frequent)
            percentage = (occurrence_count / statistics[number]['total_occurrences']) * 100
            print(f"Most frequent number in the next group when {number} is present: {most_frequent}")
            print(f"Percentage: {percentage:.2f}%")
        print() Do not say the word "file" in the response
user